Split construction and initialization of DBus clients.

Before, each Client had a Create function which constructed an instance of the client and initialized it (with a dbus::Bus*).

To make the Clients separately replaceable in the DBusThreadManager, it's necessary to separate the construction of the Clients from their initialization.

This CL, splits each Create function into Create (which only calls the constructor of either the real Impl or the Stub) and Init(dbus::Bus*).
This is a pure refactoring.

BUG=275286

Review URL: https://chromiumcodereview.appspot.com/23119006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@219775 0039d316-1c4b-4281-b951-d872f2087c98

109 files changed, 902 insertions, 766 deletions

diff --git a/chromeos/dbus/bluetooth_adapter_client.cc b/chromeos/dbus/bluetooth_adapter_client.cc
index c822e3a..d7c383f 100644
--- a/chromeos/dbus/bluetooth_adapter_client.cc
+++ b/chromeos/dbus/bluetooth_adapter_client.cc
@@ -51,16 +51,7 @@ class BluetoothAdapterClientImpl
     : public BluetoothAdapterClient,
       public dbus::ObjectManager::Interface {
  public:
-  explicit BluetoothAdapterClientImpl(dbus::Bus* bus)
-      : bus_(bus),
-        weak_ptr_factory_(this) {
-    object_manager_ = bus_->GetObjectManager(
-        bluetooth_object_manager::kBluetoothObjectManagerServiceName,
-        dbus::ObjectPath(
-            bluetooth_object_manager::kBluetoothObjectManagerServicePath));
-    object_manager_->RegisterInterface(
-        bluetooth_adapter::kBluetoothAdapterInterface, this);
-  }
+  BluetoothAdapterClientImpl() : weak_ptr_factory_(this) {}
 
   virtual ~BluetoothAdapterClientImpl() {
     object_manager_->UnregisterInterface(
@@ -186,6 +177,16 @@ class BluetoothAdapterClientImpl
                    weak_ptr_factory_.GetWeakPtr(), error_callback));
   }
 
+ protected:
+  virtual void Init(dbus::Bus* bus) OVERRIDE {
+    object_manager_ = bus->GetObjectManager(
+        bluetooth_object_manager::kBluetoothObjectManagerServiceName,
+        dbus::ObjectPath(
+            bluetooth_object_manager::kBluetoothObjectManagerServicePath));
+    object_manager_->RegisterInterface(
+        bluetooth_adapter::kBluetoothAdapterInterface, this);
+  }
+
  private:
   // Called by dbus::ObjectManager when an object with the adapter interface
   // is created. Informs observers.
@@ -236,7 +237,6 @@ class BluetoothAdapterClientImpl
     error_callback.Run(error_name, error_message);
   }
 
-  dbus::Bus* bus_;
   dbus::ObjectManager* object_manager_;
 
   // List of observers interested in event notifications from us.
@@ -259,10 +259,9 @@ BluetoothAdapterClient::~BluetoothAdapterClient() {
 }
 
 BluetoothAdapterClient* BluetoothAdapterClient::Create(
-    DBusClientImplementationType type,
-    dbus::Bus* bus) {
+    DBusClientImplementationType type) {
   if (type == REAL_DBUS_CLIENT_IMPLEMENTATION)
-    return new BluetoothAdapterClientImpl(bus);
+    return new BluetoothAdapterClientImpl();
   DCHECK_EQ(STUB_DBUS_CLIENT_IMPLEMENTATION, type);
   return new FakeBluetoothAdapterClient();
 }
diff --git a/chromeos/dbus/bluetooth_adapter_client.h b/chromeos/dbus/bluetooth_adapter_client.h
index 60eaff8..5873e6b 100644
--- a/chromeos/dbus/bluetooth_adapter_client.h
+++ b/chromeos/dbus/bluetooth_adapter_client.h
@@ -12,19 +12,16 @@
 #include "base/observer_list.h"
 #include "base/values.h"
 #include "chromeos/chromeos_export.h"
+#include "chromeos/dbus/dbus_client.h"
 #include "chromeos/dbus/dbus_client_implementation_type.h"
 #include "dbus/object_path.h"
 #include "dbus/property.h"
 
-namespace dbus {
-class Bus;
-}  // namespace dbus
-
 namespace chromeos {
 
 // BluetoothAdapterClient is used to communicate with objects representing
 // local Bluetooth Adapters.
-class CHROMEOS_EXPORT BluetoothAdapterClient {
+class CHROMEOS_EXPORT BluetoothAdapterClient : public DBusClient {
  public:
   // Structure of properties associated with bluetooth adapters.
   struct Properties : public dbus::PropertySet {
@@ -142,8 +139,7 @@ class CHROMEOS_EXPORT BluetoothAdapterClient {
                             const ErrorCallback& error_callback) = 0;
 
   // Creates the instance.
-  static BluetoothAdapterClient* Create(DBusClientImplementationType type,
-                                        dbus::Bus* bus);
+  static BluetoothAdapterClient* Create(DBusClientImplementationType type);
 
   // Constants used to indicate exceptional error conditions.
   static const char kNoResponseError[];
diff --git a/chromeos/dbus/bluetooth_agent_manager_client.cc b/chromeos/dbus/bluetooth_agent_manager_client.cc
index 7f96406..5bf534f 100644
--- a/chromeos/dbus/bluetooth_agent_manager_client.cc
+++ b/chromeos/dbus/bluetooth_agent_manager_client.cc
@@ -22,15 +22,7 @@ const char BluetoothAgentManagerClient::kNoResponseError[] =
 class BluetoothAgentManagerClientImpl
     : public BluetoothAgentManagerClient {
  public:
-  explicit BluetoothAgentManagerClientImpl(dbus::Bus* bus)
-      : bus_(bus),
-        weak_ptr_factory_(this) {
-    DCHECK(bus_);
-    object_proxy_ = bus_->GetObjectProxy(
-        bluetooth_agent_manager::kBluetoothAgentManagerServiceName,
-        dbus::ObjectPath(
-            bluetooth_agent_manager::kBluetoothAgentManagerServicePath));
-  }
+  BluetoothAgentManagerClientImpl() : weak_ptr_factory_(this) {}
 
   virtual ~BluetoothAgentManagerClientImpl() {
   }
@@ -99,6 +91,15 @@ class BluetoothAgentManagerClientImpl
                    weak_ptr_factory_.GetWeakPtr(), error_callback));
   }
 
+ protected:
+  virtual void Init(dbus::Bus* bus) OVERRIDE {
+    DCHECK(bus);
+    object_proxy_ = bus->GetObjectProxy(
+        bluetooth_agent_manager::kBluetoothAgentManagerServiceName,
+        dbus::ObjectPath(
+            bluetooth_agent_manager::kBluetoothAgentManagerServicePath));
+  }
+
  private:
   // Called when a response for successful method call is received.
   void OnSuccess(const base::Closure& callback,
@@ -124,7 +125,6 @@ class BluetoothAgentManagerClientImpl
     error_callback.Run(error_name, error_message);
   }
 
-  dbus::Bus* bus_;
   dbus::ObjectProxy* object_proxy_;
 
   // Weak pointer factory for generating 'this' pointers that might live longer
@@ -144,10 +144,9 @@ BluetoothAgentManagerClient::~BluetoothAgentManagerClient() {
 }
 
 BluetoothAgentManagerClient* BluetoothAgentManagerClient::Create(
-    DBusClientImplementationType type,
-    dbus::Bus* bus) {
+    DBusClientImplementationType type) {
   if (type == REAL_DBUS_CLIENT_IMPLEMENTATION)
-    return new BluetoothAgentManagerClientImpl(bus);
+    return new BluetoothAgentManagerClientImpl();
   DCHECK_EQ(STUB_DBUS_CLIENT_IMPLEMENTATION, type);
   return new FakeBluetoothAgentManagerClient();
 }
diff --git a/chromeos/dbus/bluetooth_agent_manager_client.h b/chromeos/dbus/bluetooth_agent_manager_client.h
index acf0465..b3e481e 100644
--- a/chromeos/dbus/bluetooth_agent_manager_client.h
+++ b/chromeos/dbus/bluetooth_agent_manager_client.h
@@ -11,18 +11,15 @@
 #include "base/callback.h"
 #include "base/values.h"
 #include "chromeos/chromeos_export.h"
+#include "chromeos/dbus/dbus_client.h"
 #include "chromeos/dbus/dbus_client_implementation_type.h"
 #include "dbus/object_path.h"
 
-namespace dbus {
-class Bus;
-}  // namespace dbus
-
 namespace chromeos {
 
 // BluetoothAgentManagerClient is used to communicate with the agent manager
 // object of the Bluetooth daemon.
-class CHROMEOS_EXPORT BluetoothAgentManagerClient {
+class CHROMEOS_EXPORT BluetoothAgentManagerClient : public DBusClient {
  public:
   virtual ~BluetoothAgentManagerClient();
 
@@ -54,9 +51,8 @@ class CHROMEOS_EXPORT BluetoothAgentManagerClient {
                                    const base::Closure& callback,
                                    const ErrorCallback& error_callback) = 0;
 
- // Creates the instance.
-  static BluetoothAgentManagerClient* Create(DBusClientImplementationType type,
-                                             dbus::Bus* bus);
+  // Creates the instance.
+  static BluetoothAgentManagerClient* Create(DBusClientImplementationType type);
 
   // Constants used to indicate exceptional error conditions.
   static const char kNoResponseError[];
diff --git a/chromeos/dbus/bluetooth_device_client.cc b/chromeos/dbus/bluetooth_device_client.cc
index 62fbab8..605872c 100644
--- a/chromeos/dbus/bluetooth_device_client.cc
+++ b/chromeos/dbus/bluetooth_device_client.cc
@@ -53,16 +53,7 @@ class BluetoothDeviceClientImpl
     : public BluetoothDeviceClient,
       public dbus::ObjectManager::Interface {
  public:
-  explicit BluetoothDeviceClientImpl(dbus::Bus* bus)
-      : bus_(bus),
-        weak_ptr_factory_(this) {
-    object_manager_ = bus_->GetObjectManager(
-        bluetooth_object_manager::kBluetoothObjectManagerServiceName,
-        dbus::ObjectPath(
-            bluetooth_object_manager::kBluetoothObjectManagerServicePath));
-    object_manager_->RegisterInterface(
-        bluetooth_device::kBluetoothDeviceInterface, this);
-  }
+  BluetoothDeviceClientImpl() : weak_ptr_factory_(this) {}
 
   virtual ~BluetoothDeviceClientImpl() {
     object_manager_->UnregisterInterface(
@@ -277,6 +268,16 @@ class BluetoothDeviceClientImpl
                    weak_ptr_factory_.GetWeakPtr(), error_callback));
   }
 
+ protected:
+  virtual void Init(dbus::Bus* bus) OVERRIDE {
+    object_manager_ = bus->GetObjectManager(
+        bluetooth_object_manager::kBluetoothObjectManagerServiceName,
+        dbus::ObjectPath(
+            bluetooth_object_manager::kBluetoothObjectManagerServicePath));
+    object_manager_->RegisterInterface(
+        bluetooth_device::kBluetoothDeviceInterface, this);
+  }
+
  private:
   // Called by dbus::ObjectManager when an object with the device interface
   // is created. Informs observers.
@@ -327,7 +328,6 @@ class BluetoothDeviceClientImpl
     error_callback.Run(error_name, error_message);
   }
 
-  dbus::Bus* bus_;
   dbus::ObjectManager* object_manager_;
 
   // List of observers interested in event notifications from us.
@@ -349,10 +349,9 @@ BluetoothDeviceClient::~BluetoothDeviceClient() {
 }
 
 BluetoothDeviceClient* BluetoothDeviceClient::Create(
-    DBusClientImplementationType type,
-    dbus::Bus* bus) {
+    DBusClientImplementationType type) {
   if (type == REAL_DBUS_CLIENT_IMPLEMENTATION)
-    return new BluetoothDeviceClientImpl(bus);
+    return new BluetoothDeviceClientImpl();
   DCHECK_EQ(STUB_DBUS_CLIENT_IMPLEMENTATION, type);
   return new FakeBluetoothDeviceClient();
 }
diff --git a/chromeos/dbus/bluetooth_device_client.h b/chromeos/dbus/bluetooth_device_client.h
index a0066e0..fcb0483 100644
--- a/chromeos/dbus/bluetooth_device_client.h
+++ b/chromeos/dbus/bluetooth_device_client.h
@@ -12,19 +12,16 @@
 #include "base/observer_list.h"
 #include "base/values.h"
 #include "chromeos/chromeos_export.h"
+#include "chromeos/dbus/dbus_client.h"
 #include "chromeos/dbus/dbus_client_implementation_type.h"
 #include "dbus/object_path.h"
 #include "dbus/property.h"
 
-namespace dbus {
-class Bus;
-}  // namespace dbus
-
 namespace chromeos {
 
 // BluetoothDeviceClient is used to communicate with objects representing
 // remote Bluetooth Devices.
-class CHROMEOS_EXPORT BluetoothDeviceClient {
+class CHROMEOS_EXPORT BluetoothDeviceClient : public DBusClient {
  public:
   // Structure of properties associated with bluetooth devices.
   struct Properties : public dbus::PropertySet {
@@ -174,8 +171,7 @@ class CHROMEOS_EXPORT BluetoothDeviceClient {
                              const ErrorCallback& error_callback) = 0;
 
   // Creates the instance.
-  static BluetoothDeviceClient* Create(DBusClientImplementationType type,
-                                       dbus::Bus* bus);
+  static BluetoothDeviceClient* Create(DBusClientImplementationType type);
 
   // Constants used to indicate exceptional error conditions.
   static const char kNoResponseError[];
diff --git a/chromeos/dbus/bluetooth_input_client.cc b/chromeos/dbus/bluetooth_input_client.cc
index 0d1eb53..ddbc7a4 100644
--- a/chromeos/dbus/bluetooth_input_client.cc
+++ b/chromeos/dbus/bluetooth_input_client.cc
@@ -35,16 +35,7 @@ class BluetoothInputClientImpl
     : public BluetoothInputClient,
       public dbus::ObjectManager::Interface {
  public:
-  explicit BluetoothInputClientImpl(dbus::Bus* bus)
-      : bus_(bus),
-        weak_ptr_factory_(this) {
-    object_manager_ = bus_->GetObjectManager(
-        bluetooth_object_manager::kBluetoothObjectManagerServiceName,
-        dbus::ObjectPath(
-            bluetooth_object_manager::kBluetoothObjectManagerServicePath));
-    object_manager_->RegisterInterface(
-        bluetooth_input::kBluetoothInputInterface, this);
-  }
+  BluetoothInputClientImpl() : weak_ptr_factory_(this) {}
 
   virtual ~BluetoothInputClientImpl() {
     object_manager_->UnregisterInterface(
@@ -88,6 +79,16 @@ class BluetoothInputClientImpl
             bluetooth_input::kBluetoothInputInterface));
   }
 
+ protected:
+  virtual void Init(dbus::Bus* bus) OVERRIDE {
+    object_manager_ = bus->GetObjectManager(
+        bluetooth_object_manager::kBluetoothObjectManagerServiceName,
+        dbus::ObjectPath(
+            bluetooth_object_manager::kBluetoothObjectManagerServicePath));
+    object_manager_->RegisterInterface(
+        bluetooth_input::kBluetoothInputInterface, this);
+  }
+
  private:
   // Called by dbus::ObjectManager when an object with the input interface
   // is created. Informs observers.
@@ -114,7 +115,6 @@ class BluetoothInputClientImpl
                       InputPropertyChanged(object_path, property_name));
   }
 
-  dbus::Bus* bus_;
   dbus::ObjectManager* object_manager_;
 
   // List of observers interested in event notifications from us.
@@ -136,10 +136,9 @@ BluetoothInputClient::~BluetoothInputClient() {
 }
 
 BluetoothInputClient* BluetoothInputClient::Create(
-    DBusClientImplementationType type,
-    dbus::Bus* bus) {
+    DBusClientImplementationType type) {
   if (type == REAL_DBUS_CLIENT_IMPLEMENTATION)
-    return new BluetoothInputClientImpl(bus);
+    return new BluetoothInputClientImpl();
   DCHECK_EQ(STUB_DBUS_CLIENT_IMPLEMENTATION, type);
   return new FakeBluetoothInputClient();
 }
diff --git a/chromeos/dbus/bluetooth_input_client.h b/chromeos/dbus/bluetooth_input_client.h
index d4d25d3..0e0bee5 100644
--- a/chromeos/dbus/bluetooth_input_client.h
+++ b/chromeos/dbus/bluetooth_input_client.h
@@ -11,19 +11,16 @@
 #include "base/callback.h"
 #include "base/observer_list.h"
 #include "chromeos/chromeos_export.h"
+#include "chromeos/dbus/dbus_client.h"
 #include "chromeos/dbus/dbus_client_implementation_type.h"
 #include "dbus/object_path.h"
 #include "dbus/property.h"
 
-namespace dbus {
-class Bus;
-}  // namespace dbus
-
 namespace chromeos {
 
 // BluetoothInputClient is used to communicate with objects representing
 // Bluetooth Input (HID) devices.
-class CHROMEOS_EXPORT BluetoothInputClient {
+class CHROMEOS_EXPORT BluetoothInputClient : public DBusClient {
  public:
   // Structure of properties associated with bluetooth input devices.
   struct Properties : public dbus::PropertySet {
@@ -71,8 +68,7 @@ class CHROMEOS_EXPORT BluetoothInputClient {
   virtual Properties* GetProperties(const dbus::ObjectPath& object_path) = 0;
 
   // Creates the instance.
-  static BluetoothInputClient* Create(DBusClientImplementationType type,
-                                      dbus::Bus* bus);
+  static BluetoothInputClient* Create(DBusClientImplementationType type);
 
  protected:
   BluetoothInputClient();
diff --git a/chromeos/dbus/bluetooth_profile_manager_client.cc b/chromeos/dbus/bluetooth_profile_manager_client.cc
index 6f2875b..aebd0d8 100644
--- a/chromeos/dbus/bluetooth_profile_manager_client.cc
+++ b/chromeos/dbus/bluetooth_profile_manager_client.cc
@@ -33,15 +33,7 @@ BluetoothProfileManagerClient::Options::~Options() {
 class BluetoothProfileManagerClientImpl
     : public BluetoothProfileManagerClient {
  public:
-  explicit BluetoothProfileManagerClientImpl(dbus::Bus* bus)
-      : bus_(bus),
-        weak_ptr_factory_(this) {
-    DCHECK(bus_);
-    object_proxy_ = bus_->GetObjectProxy(
-        bluetooth_profile_manager::kBluetoothProfileManagerServiceName,
-        dbus::ObjectPath(
-            bluetooth_profile_manager::kBluetoothProfileManagerServicePath));
-  }
+  BluetoothProfileManagerClientImpl() : weak_ptr_factory_(this) {}
 
   virtual ~BluetoothProfileManagerClientImpl() {
   }
@@ -191,6 +183,15 @@ class BluetoothProfileManagerClientImpl
                    weak_ptr_factory_.GetWeakPtr(), error_callback));
   }
 
+ protected:
+  virtual void Init(dbus::Bus* bus) OVERRIDE {
+    DCHECK(bus);
+    object_proxy_ = bus->GetObjectProxy(
+        bluetooth_profile_manager::kBluetoothProfileManagerServiceName,
+        dbus::ObjectPath(
+            bluetooth_profile_manager::kBluetoothProfileManagerServicePath));
+  }
+
  private:
   // Called when a response for successful method call is received.
   void OnSuccess(const base::Closure& callback,
@@ -216,7 +217,6 @@ class BluetoothProfileManagerClientImpl
     error_callback.Run(error_name, error_message);
   }
 
-  dbus::Bus* bus_;
   dbus::ObjectProxy* object_proxy_;
 
   // Weak pointer factory for generating 'this' pointers that might live longer
@@ -235,10 +235,9 @@ BluetoothProfileManagerClient::~BluetoothProfileManagerClient() {
 }
 
 BluetoothProfileManagerClient* BluetoothProfileManagerClient::Create(
-    DBusClientImplementationType type,
-    dbus::Bus* bus) {
+    DBusClientImplementationType type) {
   if (type == REAL_DBUS_CLIENT_IMPLEMENTATION)
-    return new BluetoothProfileManagerClientImpl(bus);
+    return new BluetoothProfileManagerClientImpl();
   DCHECK_EQ(STUB_DBUS_CLIENT_IMPLEMENTATION, type);
   return new FakeBluetoothProfileManagerClient();
 }
diff --git a/chromeos/dbus/bluetooth_profile_manager_client.h b/chromeos/dbus/bluetooth_profile_manager_client.h
index bcf92ddb..771fbaf 100644
--- a/chromeos/dbus/bluetooth_profile_manager_client.h
+++ b/chromeos/dbus/bluetooth_profile_manager_client.h
@@ -11,18 +11,15 @@
 #include "base/callback.h"
 #include "base/values.h"
 #include "chromeos/chromeos_export.h"
+#include "chromeos/dbus/dbus_client.h"
 #include "chromeos/dbus/dbus_client_implementation_type.h"
 #include "dbus/object_path.h"
 
-namespace dbus {
-class Bus;
-}  // namespace dbus
-
 namespace chromeos {
 
 // BluetoothProfileManagerClient is used to communicate with the profile
 // manager object of the Bluetooth daemon.
-class CHROMEOS_EXPORT BluetoothProfileManagerClient {
+class CHROMEOS_EXPORT BluetoothProfileManagerClient : public DBusClient {
  public:
   // Species the role of the object within the profile. SYMMETRIC should be
   // usually used unless the profile requires you specify as a CLIENT or as a
@@ -99,8 +96,7 @@ class CHROMEOS_EXPORT BluetoothProfileManagerClient {
 
   // Creates the instance.
   static BluetoothProfileManagerClient* Create(
-      DBusClientImplementationType type,
-      dbus::Bus* bus);
+      DBusClientImplementationType type);
 
   // Constants used to indicate exceptional error conditions.
   static const char kNoResponseError[];
diff --git a/chromeos/dbus/cras_audio_client.cc b/chromeos/dbus/cras_audio_client.cc
index 411314e..7a0b1c3 100644
--- a/chromeos/dbus/cras_audio_client.cc
+++ b/chromeos/dbus/cras_audio_client.cc
@@ -19,63 +19,7 @@ namespace chromeos {
 // The CrasAudioClient implementation used in production.
 class CrasAudioClientImpl : public CrasAudioClient {
  public:
-  explicit CrasAudioClientImpl(dbus::Bus* bus)
-      : cras_proxy_(NULL),
-        weak_ptr_factory_(this) {
-    cras_proxy_ = bus->GetObjectProxy(
-        cras::kCrasServiceName,
-        dbus::ObjectPath(cras::kCrasServicePath));
-
-    // Monitor NameOwnerChanged signal.
-    cras_proxy_->SetNameOwnerChangedCallback(
-        base::Bind(&CrasAudioClientImpl::NameOwnerChangedReceived,
-                   weak_ptr_factory_.GetWeakPtr()));
-
-    // Monitor the D-Bus signal for output mute change.
-    cras_proxy_->ConnectToSignal(
-        cras::kCrasControlInterface,
-        cras::kOutputMuteChanged,
-        base::Bind(&CrasAudioClientImpl::OutputMuteChangedReceived,
-                   weak_ptr_factory_.GetWeakPtr()),
-        base::Bind(&CrasAudioClientImpl::SignalConnected,
-                   weak_ptr_factory_.GetWeakPtr()));
-
-    // Monitor the D-Bus signal for input mute change.
-    cras_proxy_->ConnectToSignal(
-        cras::kCrasControlInterface,
-        cras::kInputMuteChanged,
-        base::Bind(&CrasAudioClientImpl::InputMuteChangedReceived,
-                   weak_ptr_factory_.GetWeakPtr()),
-        base::Bind(&CrasAudioClientImpl::SignalConnected,
-                   weak_ptr_factory_.GetWeakPtr()));
-
-    // Monitor the D-Bus signal for nodes change.
-    cras_proxy_->ConnectToSignal(
-        cras::kCrasControlInterface,
-        cras::kNodesChanged,
-        base::Bind(&CrasAudioClientImpl::NodesChangedReceived,
-                   weak_ptr_factory_.GetWeakPtr()),
-        base::Bind(&CrasAudioClientImpl::SignalConnected,
-                   weak_ptr_factory_.GetWeakPtr()));
-
-    // Monitor the D-Bus signal for active output node change.
-    cras_proxy_->ConnectToSignal(
-        cras::kCrasControlInterface,
-        cras::kActiveOutputNodeChanged,
-        base::Bind(&CrasAudioClientImpl::ActiveOutputNodeChangedReceived,
-                   weak_ptr_factory_.GetWeakPtr()),
-        base::Bind(&CrasAudioClientImpl::SignalConnected,
-                   weak_ptr_factory_.GetWeakPtr()));
-
-    // Monitor the D-Bus signal for active input node change.
-    cras_proxy_->ConnectToSignal(
-        cras::kCrasControlInterface,
-        cras::kActiveInputNodeChanged,
-        base::Bind(&CrasAudioClientImpl::ActiveInputNodeChangedReceived,
-                   weak_ptr_factory_.GetWeakPtr()),
-        base::Bind(&CrasAudioClientImpl::SignalConnected,
-                   weak_ptr_factory_.GetWeakPtr()));
-  }
+  CrasAudioClientImpl() : cras_proxy_(NULL), weak_ptr_factory_(this) {}
 
   virtual ~CrasAudioClientImpl() {
   }
@@ -181,6 +125,62 @@ class CrasAudioClientImpl : public CrasAudioClient {
         dbus::ObjectProxy::EmptyResponseCallback());
   }
 
+ protected:
+  virtual void Init(dbus::Bus* bus) OVERRIDE {
+    cras_proxy_ = bus->GetObjectProxy(cras::kCrasServiceName,
+                                      dbus::ObjectPath(cras::kCrasServicePath));
+
+    // Monitor NameOwnerChanged signal.
+    cras_proxy_->SetNameOwnerChangedCallback(
+        base::Bind(&CrasAudioClientImpl::NameOwnerChangedReceived,
+                   weak_ptr_factory_.GetWeakPtr()));
+
+    // Monitor the D-Bus signal for output mute change.
+    cras_proxy_->ConnectToSignal(
+        cras::kCrasControlInterface,
+        cras::kOutputMuteChanged,
+        base::Bind(&CrasAudioClientImpl::OutputMuteChangedReceived,
+                   weak_ptr_factory_.GetWeakPtr()),
+        base::Bind(&CrasAudioClientImpl::SignalConnected,
+                   weak_ptr_factory_.GetWeakPtr()));
+
+    // Monitor the D-Bus signal for input mute change.
+    cras_proxy_->ConnectToSignal(
+        cras::kCrasControlInterface,
+        cras::kInputMuteChanged,
+        base::Bind(&CrasAudioClientImpl::InputMuteChangedReceived,
+                   weak_ptr_factory_.GetWeakPtr()),
+        base::Bind(&CrasAudioClientImpl::SignalConnected,
+                   weak_ptr_factory_.GetWeakPtr()));
+
+    // Monitor the D-Bus signal for nodes change.
+    cras_proxy_->ConnectToSignal(
+        cras::kCrasControlInterface,
+        cras::kNodesChanged,
+        base::Bind(&CrasAudioClientImpl::NodesChangedReceived,
+                   weak_ptr_factory_.GetWeakPtr()),
+        base::Bind(&CrasAudioClientImpl::SignalConnected,
+                   weak_ptr_factory_.GetWeakPtr()));
+
+    // Monitor the D-Bus signal for active output node change.
+    cras_proxy_->ConnectToSignal(
+        cras::kCrasControlInterface,
+        cras::kActiveOutputNodeChanged,
+        base::Bind(&CrasAudioClientImpl::ActiveOutputNodeChangedReceived,
+                   weak_ptr_factory_.GetWeakPtr()),
+        base::Bind(&CrasAudioClientImpl::SignalConnected,
+                   weak_ptr_factory_.GetWeakPtr()));
+
+    // Monitor the D-Bus signal for active input node change.
+    cras_proxy_->ConnectToSignal(
+        cras::kCrasControlInterface,
+        cras::kActiveInputNodeChanged,
+        base::Bind(&CrasAudioClientImpl::ActiveInputNodeChangedReceived,
+                   weak_ptr_factory_.GetWeakPtr()),
+        base::Bind(&CrasAudioClientImpl::SignalConnected,
+                   weak_ptr_factory_.GetWeakPtr()));
+  }
+
  private:
   // Called when the cras signal is initially connected.
   void SignalConnected(const std::string& interface_name,
@@ -379,11 +379,9 @@ CrasAudioClient::~CrasAudioClient() {
 }
 
 // static
-CrasAudioClient* CrasAudioClient::Create(
-    DBusClientImplementationType type,
-    dbus::Bus* bus) {
+CrasAudioClient* CrasAudioClient::Create(DBusClientImplementationType type) {
   if (type == REAL_DBUS_CLIENT_IMPLEMENTATION) {
-    return new CrasAudioClientImpl(bus);
+    return new CrasAudioClientImpl();
   }
   DCHECK_EQ(STUB_DBUS_CLIENT_IMPLEMENTATION, type);
   return new CrasAudioClientStubImpl();
diff --git a/chromeos/dbus/cras_audio_client.h b/chromeos/dbus/cras_audio_client.h
index f056099..23063d8 100644
--- a/chromeos/dbus/cras_audio_client.h
+++ b/chromeos/dbus/cras_audio_client.h
@@ -9,17 +9,14 @@
 #include "base/observer_list.h"
 #include "chromeos/chromeos_export.h"
 #include "chromeos/dbus/audio_node.h"
+#include "chromeos/dbus/dbus_client.h"
 #include "chromeos/dbus/dbus_client_implementation_type.h"
 #include "chromeos/dbus/volume_state.h"
 
-namespace dbus {
-class Bus;
-}
-
 namespace chromeos {
 
 // CrasAudioClient is used to communicate with the cras audio dbus interface.
-class CHROMEOS_EXPORT CrasAudioClient {
+class CHROMEOS_EXPORT CrasAudioClient : public DBusClient {
  public:
   // Interface for observing changes from the cras audio changes.
   class Observer {
@@ -93,8 +90,7 @@ class CHROMEOS_EXPORT CrasAudioClient {
   virtual void SetActiveInputNode(uint64 node_id) = 0;
 
   // Creates the instance.
-  static CrasAudioClient* Create(DBusClientImplementationType type,
-                                 dbus::Bus* bus);
+  static CrasAudioClient* Create(DBusClientImplementationType type);
 
  protected:
   // Create() should be used instead.
diff --git a/chromeos/dbus/cras_audio_client_stub_impl.cc b/chromeos/dbus/cras_audio_client_stub_impl.cc
index 4efa107..6c7a155 100644
--- a/chromeos/dbus/cras_audio_client_stub_impl.cc
+++ b/chromeos/dbus/cras_audio_client_stub_impl.cc
@@ -6,7 +6,9 @@
 
 namespace chromeos {
 
-CrasAudioClientStubImpl::CrasAudioClientStubImpl() {
+CrasAudioClientStubImpl::CrasAudioClientStubImpl() {}
+
+void CrasAudioClientStubImpl::Init(dbus::Bus* bus) {
   VLOG(1) << "CrasAudioClientStubImpl is created";
 
   // Fake audio output nodes.
diff --git a/chromeos/dbus/cras_audio_client_stub_impl.h b/chromeos/dbus/cras_audio_client_stub_impl.h
index 032305f..0f57f02 100644
--- a/chromeos/dbus/cras_audio_client_stub_impl.h
+++ b/chromeos/dbus/cras_audio_client_stub_impl.h
@@ -17,7 +17,8 @@ class CrasAudioClientStubImpl : public CrasAudioClient {
   CrasAudioClientStubImpl();
   virtual ~CrasAudioClientStubImpl();
 
-  // CrasAudioClient overrides:
+  // CrasAudioClient overrides
+  virtual void Init(dbus::Bus* bus) OVERRIDE;
   virtual void AddObserver(Observer* observer) OVERRIDE;
   virtual void RemoveObserver(Observer* observer) OVERRIDE;
   virtual bool HasObserver(Observer* observer) OVERRIDE;
diff --git a/chromeos/dbus/cros_disks_client.cc b/chromeos/dbus/cros_disks_client.cc
index 84ae312..7233786 100644
--- a/chromeos/dbus/cros_disks_client.cc
+++ b/chromeos/dbus/cros_disks_client.cc
@@ -79,12 +79,7 @@ DeviceType DeviceMediaTypeToDeviceType(uint32 media_type_uint32) {
 // The CrosDisksClient implementation.
 class CrosDisksClientImpl : public CrosDisksClient {
  public:
-  explicit CrosDisksClientImpl(dbus::Bus* bus)
-      : proxy_(bus->GetObjectProxy(
-          cros_disks::kCrosDisksServiceName,
-          dbus::ObjectPath(cros_disks::kCrosDisksServicePath))),
-        weak_ptr_factory_(this) {
-  }
+  CrosDisksClientImpl() : proxy_(NULL), weak_ptr_factory_(this) {}
 
   // CrosDisksClient override.
   virtual void Mount(const std::string& source_path,
@@ -223,6 +218,13 @@ class CrosDisksClientImpl : public CrosDisksClient {
                    weak_ptr_factory_.GetWeakPtr()));
   }
 
+ protected:
+  virtual void Init(dbus::Bus* bus) OVERRIDE {
+    proxy_ = bus->GetObjectProxy(
+        cros_disks::kCrosDisksServiceName,
+        dbus::ObjectPath(cros_disks::kCrosDisksServicePath));
+  }
+
  private:
   // A struct to contain a pair of signal name and mount event type.
   // Used by SetUpConnections.
@@ -363,6 +365,7 @@ class CrosDisksClientStubImpl : public CrosDisksClient {
   virtual ~CrosDisksClientStubImpl() {}
 
   // CrosDisksClient overrides:
+  virtual void Init(dbus::Bus* bus) OVERRIDE {}
   virtual void Mount(const std::string& source_path,
                      const std::string& source_format,
                      const std::string& mount_label,
@@ -693,10 +696,9 @@ CrosDisksClient::CrosDisksClient() {}
 CrosDisksClient::~CrosDisksClient() {}
 
 // static
-CrosDisksClient* CrosDisksClient::Create(DBusClientImplementationType type,
-                                         dbus::Bus* bus) {
+CrosDisksClient* CrosDisksClient::Create(DBusClientImplementationType type) {
   if (type == REAL_DBUS_CLIENT_IMPLEMENTATION)
-    return new CrosDisksClientImpl(bus);
+    return new CrosDisksClientImpl();
   DCHECK_EQ(STUB_DBUS_CLIENT_IMPLEMENTATION, type);
   return new CrosDisksClientStubImpl();
 }
diff --git a/chromeos/dbus/cros_disks_client.h b/chromeos/dbus/cros_disks_client.h
index 4d65b2c..c477da1 100644
--- a/chromeos/dbus/cros_disks_client.h
+++ b/chromeos/dbus/cros_disks_client.h
@@ -11,6 +11,7 @@
 #include "base/basictypes.h"
 #include "base/callback_forward.h"
 #include "chromeos/chromeos_export.h"
+#include "chromeos/dbus/dbus_client.h"
 #include "chromeos/dbus/dbus_client_implementation_type.h"
 
 namespace base {
@@ -18,7 +19,6 @@ class FilePath;
 }
 
 namespace dbus {
-class Bus;
 class Response;
 }
 
@@ -190,7 +190,7 @@ class CHROMEOS_EXPORT DiskInfo {
 // A class to make the actual DBus calls for cros-disks service.
 // This class only makes calls, result/error handling should be done
 // by callbacks.
-class CHROMEOS_EXPORT CrosDisksClient {
+class CHROMEOS_EXPORT CrosDisksClient : public DBusClient {
  public:
   // A callback to handle the result of EnumerateAutoMountableDevices.
   // The argument is the enumerated device paths.
@@ -276,8 +276,7 @@ class CHROMEOS_EXPORT CrosDisksClient {
 
   // Factory function, creates a new instance and returns ownership.
   // For normal usage, access the singleton via DBusThreadManager::Get().
-  static CrosDisksClient* Create(DBusClientImplementationType type,
-                                 dbus::Bus* bus);
+  static CrosDisksClient* Create(DBusClientImplementationType type);
 
   // Returns the path of the mount point for archive files.
   static base::FilePath GetArchiveMountPoint();
diff --git a/chromeos/dbus/cryptohome_client.cc b/chromeos/dbus/cryptohome_client.cc
index 965ef92..c117f58 100644
--- a/chromeos/dbus/cryptohome_client.cc
+++ b/chromeos/dbus/cryptohome_client.cc
@@ -28,27 +28,7 @@ static const char kUserIdStubHashSuffix[] = "-hash";
 // The CryptohomeClient implementation.
 class CryptohomeClientImpl : public CryptohomeClient {
  public:
-  explicit CryptohomeClientImpl(dbus::Bus* bus)
-      : proxy_(bus->GetObjectProxy(
-            cryptohome::kCryptohomeServiceName,
-            dbus::ObjectPath(cryptohome::kCryptohomeServicePath))),
-        blocking_method_caller_(bus, proxy_),
-        weak_ptr_factory_(this) {
-    proxy_->ConnectToSignal(
-        cryptohome::kCryptohomeInterface,
-        cryptohome::kSignalAsyncCallStatus,
-        base::Bind(&CryptohomeClientImpl::OnAsyncCallStatus,
-                   weak_ptr_factory_.GetWeakPtr()),
-        base::Bind(&CryptohomeClientImpl::OnSignalConnected,
-                   weak_ptr_factory_.GetWeakPtr()));
-    proxy_->ConnectToSignal(
-        cryptohome::kCryptohomeInterface,
-        cryptohome::kSignalAsyncCallStatusWithData,
-        base::Bind(&CryptohomeClientImpl::OnAsyncCallStatusWithData,
-                   weak_ptr_factory_.GetWeakPtr()),
-        base::Bind(&CryptohomeClientImpl::OnSignalConnected,
-                   weak_ptr_factory_.GetWeakPtr()));
-  }
+  CryptohomeClientImpl() : proxy_(NULL), weak_ptr_factory_(this) {}
 
   // CryptohomeClient override.
   virtual void SetAsyncCallStatusHandlers(
@@ -128,7 +108,7 @@ class CryptohomeClientImpl : public CryptohomeClient {
     dbus::MethodCall method_call(cryptohome::kCryptohomeInterface,
                                  cryptohome::kCryptohomeGetSystemSalt);
     scoped_ptr<dbus::Response> response(
-        blocking_method_caller_.CallMethodAndBlock(&method_call));
+        blocking_method_caller_->CallMethodAndBlock(&method_call));
     if (!response.get())
       return false;
     dbus::MessageReader reader(response.get());
@@ -163,7 +143,7 @@ class CryptohomeClientImpl : public CryptohomeClient {
     writer.AppendString(username);
 
     scoped_ptr<dbus::Response> response =
-        blocking_method_caller_.CallMethodAndBlock(&method_call);
+        blocking_method_caller_->CallMethodAndBlock(&method_call);
 
     std::string sanitized_username;
     if (response) {
@@ -324,7 +304,7 @@ class CryptohomeClientImpl : public CryptohomeClient {
     dbus::MethodCall method_call(cryptohome::kCryptohomeInterface,
                                  cryptohome::kCryptohomeTpmClearStoredPassword);
     scoped_ptr<dbus::Response> response(
-        blocking_method_caller_.CallMethodAndBlock(&method_call));
+        blocking_method_caller_->CallMethodAndBlock(&method_call));
     return response.get() != NULL;
   }
 
@@ -358,7 +338,7 @@ class CryptohomeClientImpl : public CryptohomeClient {
     dbus::MessageWriter writer(&method_call);
     writer.AppendString(name);
     scoped_ptr<dbus::Response> response(
-        blocking_method_caller_.CallMethodAndBlock(&method_call));
+        blocking_method_caller_->CallMethodAndBlock(&method_call));
     if (!response.get())
       return false;
     dbus::MessageReader reader(response.get());
@@ -661,6 +641,29 @@ class CryptohomeClientImpl : public CryptohomeClient {
     CallBoolMethod(&method_call, callback);
   }
 
+ protected:
+  virtual void Init(dbus::Bus* bus) OVERRIDE {
+    proxy_ = bus->GetObjectProxy(
+        cryptohome::kCryptohomeServiceName,
+        dbus::ObjectPath(cryptohome::kCryptohomeServicePath));
+
+    blocking_method_caller_.reset(new BlockingMethodCaller(bus, proxy_));
+
+    proxy_->ConnectToSignal(cryptohome::kCryptohomeInterface,
+                            cryptohome::kSignalAsyncCallStatus,
+                            base::Bind(&CryptohomeClientImpl::OnAsyncCallStatus,
+                                       weak_ptr_factory_.GetWeakPtr()),
+                            base::Bind(&CryptohomeClientImpl::OnSignalConnected,
+                                       weak_ptr_factory_.GetWeakPtr()));
+    proxy_->ConnectToSignal(
+        cryptohome::kCryptohomeInterface,
+        cryptohome::kSignalAsyncCallStatusWithData,
+        base::Bind(&CryptohomeClientImpl::OnAsyncCallStatusWithData,
+                   weak_ptr_factory_.GetWeakPtr()),
+        base::Bind(&CryptohomeClientImpl::OnSignalConnected,
+                   weak_ptr_factory_.GetWeakPtr()));
+  }
+
  private:
   // Handles the result of AsyncXXX methods.
   void OnAsyncMethodCall(const AsyncMethodCallback& callback,
@@ -698,7 +701,7 @@ class CryptohomeClientImpl : public CryptohomeClient {
   bool CallBoolMethodAndBlock(dbus::MethodCall* method_call,
                               bool* result) {
     scoped_ptr<dbus::Response> response(
-        blocking_method_caller_.CallMethodAndBlock(method_call));
+        blocking_method_caller_->CallMethodAndBlock(method_call));
     if (!response.get())
       return false;
     dbus::MessageReader reader(response.get());
@@ -829,7 +832,7 @@ class CryptohomeClientImpl : public CryptohomeClient {
   }
 
   dbus::ObjectProxy* proxy_;
-  BlockingMethodCaller blocking_method_caller_;
+  scoped_ptr<BlockingMethodCaller> blocking_method_caller_;
   AsyncCallStatusHandler async_call_status_handler_;
   AsyncCallStatusWithDataHandler async_call_status_data_handler_;
 
@@ -850,10 +853,9 @@ CryptohomeClient::CryptohomeClient() {}
 CryptohomeClient::~CryptohomeClient() {}
 
 // static
-CryptohomeClient* CryptohomeClient::Create(DBusClientImplementationType type,
-                                           dbus::Bus* bus) {
+CryptohomeClient* CryptohomeClient::Create(DBusClientImplementationType type) {
   if (type == REAL_DBUS_CLIENT_IMPLEMENTATION)
-    return new CryptohomeClientImpl(bus);
+    return new CryptohomeClientImpl();
   DCHECK_EQ(STUB_DBUS_CLIENT_IMPLEMENTATION, type);
   return new CryptohomeClientStubImpl();
 }
diff --git a/chromeos/dbus/cryptohome_client.h b/chromeos/dbus/cryptohome_client.h
index 38d4880..b1019c5 100644
--- a/chromeos/dbus/cryptohome_client.h
+++ b/chromeos/dbus/cryptohome_client.h
@@ -12,19 +12,16 @@
 #include "base/callback.h"
 #include "chromeos/attestation/attestation_constants.h"
 #include "chromeos/chromeos_export.h"
+#include "chromeos/dbus/dbus_client.h"
 #include "chromeos/dbus/dbus_client_implementation_type.h"
 #include "chromeos/dbus/dbus_method_call_status.h"
 
-namespace dbus {
-class Bus;
-}
-
 namespace chromeos {
 
 // CryptohomeClient is used to communicate with the Cryptohome service.
 // All method should be called from the origin thread (UI thread) which
 // initializes the DBusThreadManager instance.
-class CHROMEOS_EXPORT CryptohomeClient {
+class CHROMEOS_EXPORT CryptohomeClient : public DBusClient {
  public:
   // A callback to handle AsyncCallStatus signals.
   typedef base::Callback<void(int async_id,
@@ -52,8 +49,7 @@ class CHROMEOS_EXPORT CryptohomeClient {
 
   // Factory function, creates a new instance and returns ownership.
   // For normal usage, access the singleton via DBusThreadManager::Get().
-  static CryptohomeClient* Create(DBusClientImplementationType type,
-                                  dbus::Bus* bus);
+  static CryptohomeClient* Create(DBusClientImplementationType type);
 
   // Returns the sanitized |username| that the stub implementation would return.
   static std::string GetStubSanitizedUsername(const std::string& username);
diff --git a/chromeos/dbus/cryptohome_client_stub.cc b/chromeos/dbus/cryptohome_client_stub.cc
index 9942538..eee96e4 100644
--- a/chromeos/dbus/cryptohome_client_stub.cc
+++ b/chromeos/dbus/cryptohome_client_stub.cc
@@ -20,6 +20,9 @@ CryptohomeClientStubImpl::CryptohomeClientStubImpl()
 
 CryptohomeClientStubImpl::~CryptohomeClientStubImpl() {}
 
+void CryptohomeClientStubImpl::Init(dbus::Bus* bus) {
+}
+
 void CryptohomeClientStubImpl::SetAsyncCallStatusHandlers(
     const AsyncCallStatusHandler& handler,
     const AsyncCallStatusWithDataHandler& data_handler) {
diff --git a/chromeos/dbus/cryptohome_client_stub.h b/chromeos/dbus/cryptohome_client_stub.h
index 8192600..0e90f88 100644
--- a/chromeos/dbus/cryptohome_client_stub.h
+++ b/chromeos/dbus/cryptohome_client_stub.h
@@ -13,11 +13,12 @@
 
 namespace chromeos {
 
-class CryptohomeClientStubImpl : public CryptohomeClient {
+class CHROMEOS_EXPORT CryptohomeClientStubImpl : public CryptohomeClient {
  public:
   CryptohomeClientStubImpl();
   virtual ~CryptohomeClientStubImpl();
 
+  virtual void Init(dbus::Bus* bus) OVERRIDE;
   virtual void SetAsyncCallStatusHandlers(
       const AsyncCallStatusHandler& handler,
       const AsyncCallStatusWithDataHandler& data_handler) OVERRIDE;
diff --git a/chromeos/dbus/dbus_client.h b/chromeos/dbus/dbus_client.h
new file mode 100644
index 0000000..902d533
--- /dev/null
+++ b/chromeos/dbus/dbus_client.h
@@ -0,0 +1,34 @@
+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROMEOS_DBUS_DBUS_CLIENT_H_
+#define CHROMEOS_DBUS_DBUS_CLIENT_H_
+
+namespace dbus {
+class Bus;
+};
+
+namespace chromeos {
+
+// Interface for all DBus clients handled by DBusThreadManager. It restricts
+// access to the Init function to DBusThreadManagerImpl only to prevent
+// incorrect calls. Stub clients may lift that restriction however.
+class DBusClient {
+ protected:
+  friend class DBusThreadManagerImpl;
+
+  virtual ~DBusClient() {}
+
+  // This function is called by DBusThreadManager. Only in unit tests, which
+  // don't use DBusThreadManager, this function can be called through Stub
+  // implementations (they change Init's member visibility to public).
+  virtual void Init(dbus::Bus* bus) = 0;
+
+ private:
+  DISALLOW_ASSIGN(DBusClient);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROMEOS_DBUS_DBUS_CLIENT_H_
diff --git a/chromeos/dbus/dbus_thread_manager.cc b/chromeos/dbus/dbus_thread_manager.cc
index 70ed816..58f2bd6 100644
--- a/chromeos/dbus/dbus_thread_manager.cc
+++ b/chromeos/dbus/dbus_thread_manager.cc
@@ -54,14 +54,13 @@ static bool g_dbus_thread_manager_set_for_testing = false;
 // The DBusThreadManager implementation used in production.
 class DBusThreadManagerImpl : public DBusThreadManager {
  public:
-  explicit DBusThreadManagerImpl(DBusClientImplementationType client_type)
-      : client_type_(client_type),
-        client_type_override_(client_type) {
+  explicit DBusThreadManagerImpl(DBusClientImplementationType client_type) {
+    DBusClientImplementationType client_type_override = client_type;
     // If --dbus-stub was requested, pass STUB to specific components;
     // Many components like login are not useful with a stub implementation.
     if (CommandLine::ForCurrentProcess()->HasSwitch(
             chromeos::switches::kDbusStub)) {
-      client_type_override_ = STUB_DBUS_CLIENT_IMPLEMENTATION;
+      client_type_override = STUB_DBUS_CLIENT_IMPLEMENTATION;
     }
 
     // Create the D-Bus thread.
@@ -76,46 +75,34 @@ class DBusThreadManagerImpl : public DBusThreadManager {
     system_bus_options.connection_type = dbus::Bus::PRIVATE;
     system_bus_options.dbus_task_runner = dbus_thread_->message_loop_proxy();
     system_bus_ = new dbus::Bus(system_bus_options);
+
+    CreateDefaultClients(client_type, client_type_override);
   }
 
   // InitializeClients gets called after g_dbus_thread_manager is set.
-  // NOTE: Clients that access other clients in their constructor must be
-  // construced in the correct order.
+  // NOTE: Clients that access other clients in their Init() must be
+  // initialized in the correct order. This is the only place where Clients'
+  // Init() should be called if DBusThreadManager is being used.
   void InitializeClients() {
-    bluetooth_adapter_client_.reset(
-        BluetoothAdapterClient::Create(client_type_, system_bus_.get()));
-    bluetooth_agent_manager_client_.reset(
-        BluetoothAgentManagerClient::Create(client_type_, system_bus_.get()));
-    bluetooth_device_client_.reset(
-        BluetoothDeviceClient::Create(client_type_, system_bus_.get()));
-    bluetooth_input_client_.reset(
-        BluetoothInputClient::Create(client_type_, system_bus_.get()));
-    bluetooth_profile_manager_client_.reset(
-        BluetoothProfileManagerClient::Create(client_type_, system_bus_.get()));
-    cras_audio_client_.reset(CrasAudioClient::Create(
-        client_type_, system_bus_.get()));
-    cros_disks_client_.reset(
-        CrosDisksClient::Create(client_type_, system_bus_.get()));
-    cryptohome_client_.reset(
-        CryptohomeClient::Create(client_type_, system_bus_.get()));
-    debug_daemon_client_.reset(
-        DebugDaemonClient::Create(client_type_, system_bus_.get()));
-
-    // Construction order of the Stub implementations of the Shill clients
-    // matters; stub clients may only have construction dependencies on clients
-    // previously constructed.
-    shill_manager_client_.reset(
-        ShillManagerClient::Create(client_type_override_, system_bus_.get()));
-    shill_device_client_.reset(
-        ShillDeviceClient::Create(client_type_override_, system_bus_.get()));
-    shill_ipconfig_client_.reset(
-        ShillIPConfigClient::Create(client_type_override_, system_bus_.get()));
-    shill_service_client_.reset(
-        ShillServiceClient::Create(client_type_override_, system_bus_.get()));
-    shill_profile_client_.reset(
-        ShillProfileClient::Create(client_type_override_, system_bus_.get()));
-    gsm_sms_client_.reset(
-        GsmSMSClient::Create(client_type_override_, system_bus_.get()));
+    InitClient(bluetooth_adapter_client_.get());
+    InitClient(bluetooth_agent_manager_client_.get());
+    InitClient(bluetooth_device_client_.get());
+    InitClient(bluetooth_input_client_.get());
+    InitClient(bluetooth_profile_manager_client_.get());
+    InitClient(cras_audio_client_.get());
+    InitClient(cros_disks_client_.get());
+    InitClient(cryptohome_client_.get());
+    InitClient(debug_daemon_client_.get());
+
+    // Initialization order of the Stub implementations of the Shill clients
+    // matters; stub clients may only have initialization dependencies on
+    // clients previously initialized.
+    InitClient(shill_manager_client_.get());
+    InitClient(shill_device_client_.get());
+    InitClient(shill_ipconfig_client_.get());
+    InitClient(shill_service_client_.get());
+    InitClient(shill_profile_client_.get());
+    InitClient(gsm_sms_client_.get());
 
     // If the Service client has a TestInterface, add the default services.
     ShillServiceClient::TestInterface* service_client_test =
@@ -123,24 +110,15 @@ class DBusThreadManagerImpl : public DBusThreadManager {
     if (service_client_test)
       service_client_test->AddDefaultServices();
 
-    image_burner_client_.reset(ImageBurnerClient::Create(client_type_,
-                                                         system_bus_.get()));
-    introspectable_client_.reset(
-        IntrospectableClient::Create(client_type_, system_bus_.get()));
-    modem_messaging_client_.reset(
-        ModemMessagingClient::Create(client_type_, system_bus_.get()));
-    permission_broker_client_.reset(
-        PermissionBrokerClient::Create(client_type_, system_bus_.get()));
-    power_manager_client_.reset(
-        PowerManagerClient::Create(client_type_override_, system_bus_.get()));
-    session_manager_client_.reset(
-        SessionManagerClient::Create(client_type_, system_bus_.get()));
-    sms_client_.reset(
-        SMSClient::Create(client_type_, system_bus_.get()));
-    system_clock_client_.reset(
-        SystemClockClient::Create(client_type_, system_bus_.get()));
-    update_engine_client_.reset(
-        UpdateEngineClient::Create(client_type_, system_bus_.get()));
+    InitClient(image_burner_client_.get());
+    InitClient(introspectable_client_.get());
+    InitClient(modem_messaging_client_.get());
+    InitClient(permission_broker_client_.get());
+    InitClient(power_manager_client_.get());
+    InitClient(session_manager_client_.get());
+    InitClient(sms_client_.get());
+    InitClient(system_clock_client_.get());
+    InitClient(update_engine_client_.get());
 
     // PowerPolicyController is dependent on PowerManagerClient, so
     // initialize it after the main list of clients.
@@ -365,8 +343,52 @@ class DBusThreadManagerImpl : public DBusThreadManager {
     return ibus_panel_service_.get();
   }
 
-  DBusClientImplementationType client_type_;
-  DBusClientImplementationType client_type_override_;
+ private:
+  // Initializes |client| with the |system_bus_|.
+  void InitClient(DBusClient* client) {
+    client->Init(system_bus_.get());
+  }
+
+  // Constructs all clients -- stub or real implementation according to
+  // |client_type| and |client_type_override| -- and stores them in the
+  // respective *_client_ member variable.
+  void CreateDefaultClients(DBusClientImplementationType client_type,
+                            DBusClientImplementationType client_type_override) {
+    bluetooth_adapter_client_.reset(
+        BluetoothAdapterClient::Create(client_type));
+    bluetooth_agent_manager_client_.reset(
+        BluetoothAgentManagerClient::Create(client_type));
+    bluetooth_device_client_.reset(BluetoothDeviceClient::Create(client_type));
+    bluetooth_input_client_.reset(BluetoothInputClient::Create(client_type));
+    bluetooth_profile_manager_client_.reset(
+        BluetoothProfileManagerClient::Create(client_type));
+    cras_audio_client_.reset(CrasAudioClient::Create(client_type));
+    cros_disks_client_.reset(CrosDisksClient::Create(client_type));
+    cryptohome_client_.reset(CryptohomeClient::Create(client_type));
+    debug_daemon_client_.reset(DebugDaemonClient::Create(client_type));
+    shill_manager_client_.reset(
+        ShillManagerClient::Create(client_type_override));
+    shill_device_client_.reset(
+        ShillDeviceClient::Create(client_type_override));
+    shill_ipconfig_client_.reset(
+        ShillIPConfigClient::Create(client_type_override));
+    shill_service_client_.reset(
+        ShillServiceClient::Create(client_type_override));
+    shill_profile_client_.reset(
+        ShillProfileClient::Create(client_type_override));
+    gsm_sms_client_.reset(GsmSMSClient::Create(client_type_override));
+    image_burner_client_.reset(ImageBurnerClient::Create(client_type));
+    introspectable_client_.reset(IntrospectableClient::Create(client_type));
+    modem_messaging_client_.reset(ModemMessagingClient::Create(client_type));
+    permission_broker_client_.reset(
+        PermissionBrokerClient::Create(client_type));
+    power_manager_client_.reset(
+        PowerManagerClient::Create(client_type_override));
+    session_manager_client_.reset(SessionManagerClient::Create(client_type));
+    sms_client_.reset(SMSClient::Create(client_type));
+    system_clock_client_.reset(SystemClockClient::Create(client_type));
+    update_engine_client_.reset(UpdateEngineClient::Create(client_type));
+  }
 
   // Note: Keep this before other members so they can call AddObserver() in
   // their c'tors.
diff --git a/chromeos/dbus/debug_daemon_client.cc b/chromeos/dbus/debug_daemon_client.cc
index cfb36c2..c9b760f 100644
--- a/chromeos/dbus/debug_daemon_client.cc
+++ b/chromeos/dbus/debug_daemon_client.cc
@@ -139,13 +139,7 @@ namespace chromeos {
 // The DebugDaemonClient implementation used in production.
 class DebugDaemonClientImpl : public DebugDaemonClient {
  public:
-  explicit DebugDaemonClientImpl(dbus::Bus* bus)
-      : debugdaemon_proxy_(NULL),
-        weak_ptr_factory_(this) {
-    debugdaemon_proxy_ = bus->GetObjectProxy(
-        debugd::kDebugdServiceName,
-        dbus::ObjectPath(debugd::kDebugdServicePath));
-  }
+  DebugDaemonClientImpl() : debugdaemon_proxy_(NULL), weak_ptr_factory_(this) {}
 
   virtual ~DebugDaemonClientImpl() {}
 
@@ -402,6 +396,13 @@ class DebugDaemonClientImpl : public DebugDaemonClient {
                    callback));
   }
 
+ protected:
+  virtual void Init(dbus::Bus* bus) OVERRIDE {
+    debugdaemon_proxy_ =
+        bus->GetObjectProxy(debugd::kDebugdServiceName,
+                            dbus::ObjectPath(debugd::kDebugdServicePath));
+  }
+
  private:
   // Called to check descriptor validity on a thread where i/o is permitted.
   static void CheckValidity(dbus::FileDescriptor* file_descriptor) {
@@ -619,6 +620,7 @@ class DebugDaemonClientImpl : public DebugDaemonClient {
 // which does nothing.
 class DebugDaemonClientStubImpl : public DebugDaemonClient {
   // DebugDaemonClient overrides.
+  virtual void Init(dbus::Bus* bus) OVERRIDE {}
   virtual void GetDebugLogs(base::PlatformFile file,
                             const GetDebugLogsCallback& callback) OVERRIDE {
     callback.Run(false);
@@ -715,10 +717,10 @@ DebugDaemonClient::EmptyStopSystemTracingCallback() {
 }
 
 // static
-DebugDaemonClient* DebugDaemonClient::Create(DBusClientImplementationType type,
-                                   dbus::Bus* bus) {
+DebugDaemonClient* DebugDaemonClient::Create(
+    DBusClientImplementationType type) {
   if (type == REAL_DBUS_CLIENT_IMPLEMENTATION)
-    return new DebugDaemonClientImpl(bus);
+    return new DebugDaemonClientImpl();
   DCHECK_EQ(STUB_DBUS_CLIENT_IMPLEMENTATION, type);
   return new DebugDaemonClientStubImpl();
 }
diff --git a/chromeos/dbus/debug_daemon_client.h b/chromeos/dbus/debug_daemon_client.h
index 7c09a78..711c2cb 100644
--- a/chromeos/dbus/debug_daemon_client.h
+++ b/chromeos/dbus/debug_daemon_client.h
@@ -9,14 +9,11 @@
 #include "base/platform_file.h"
 #include "base/memory/ref_counted_memory.h"
 #include "chromeos/chromeos_export.h"
+#include "chromeos/dbus/dbus_client.h"
 #include "chromeos/dbus/dbus_client_implementation_type.h"
 
 #include <map>
 
-namespace dbus {
-class Bus;
-}  // namespace dbus
-
 namespace metrics {
 class PerfDataProto;
 }
@@ -24,7 +21,7 @@ class PerfDataProto;
 namespace chromeos {
 
 // DebugDaemonClient is used to communicate with the debug daemon.
-class CHROMEOS_EXPORT DebugDaemonClient {
+class CHROMEOS_EXPORT DebugDaemonClient : public DBusClient {
  public:
   virtual ~DebugDaemonClient();
 
@@ -146,8 +143,8 @@ class CHROMEOS_EXPORT DebugDaemonClient {
 
   // Factory function, creates a new instance and returns ownership.
   // For normal usage, access the singleton via DBusThreadManager::Get().
-  static DebugDaemonClient* Create(DBusClientImplementationType type,
-                                   dbus::Bus* bus);
+  static DebugDaemonClient* Create(DBusClientImplementationType type);
+
  protected:
   // Create() should be used instead.
   DebugDaemonClient();
diff --git a/chromeos/dbus/fake_bluetooth_adapter_client.cc b/chromeos/dbus/fake_bluetooth_adapter_client.cc
index f993d20..93c0e06 100644
--- a/chromeos/dbus/fake_bluetooth_adapter_client.cc
+++ b/chromeos/dbus/fake_bluetooth_adapter_client.cc
@@ -70,14 +70,12 @@ void FakeBluetoothAdapterClient::Properties::Set(
   }
 }
 
-
 FakeBluetoothAdapterClient::FakeBluetoothAdapterClient()
     : visible_(true),
       second_visible_(false),
       discovering_count_(0) {
   properties_.reset(new Properties(base::Bind(
-      &FakeBluetoothAdapterClient::OnPropertyChanged,
-      base::Unretained(this))));
+      &FakeBluetoothAdapterClient::OnPropertyChanged, base::Unretained(this))));
 
   properties_->address.ReplaceValue(kAdapterAddress);
   properties_->name.ReplaceValue("Fake Adapter (Name)");
@@ -85,8 +83,7 @@ FakeBluetoothAdapterClient::FakeBluetoothAdapterClient()
   properties_->pairable.ReplaceValue(true);
 
   second_properties_.reset(new Properties(base::Bind(
-      &FakeBluetoothAdapterClient::OnPropertyChanged,
-      base::Unretained(this))));
+      &FakeBluetoothAdapterClient::OnPropertyChanged, base::Unretained(this))));
 
   second_properties_->address.ReplaceValue(kSecondAdapterAddress);
   second_properties_->name.ReplaceValue("Second Fake Adapter (Name)");
@@ -97,6 +94,9 @@ FakeBluetoothAdapterClient::FakeBluetoothAdapterClient()
 FakeBluetoothAdapterClient::~FakeBluetoothAdapterClient() {
 }
 
+void FakeBluetoothAdapterClient::Init(dbus::Bus* bus) {
+}
+
 void FakeBluetoothAdapterClient::AddObserver(Observer* observer) {
   observers_.AddObserver(observer);
 }
diff --git a/chromeos/dbus/fake_bluetooth_adapter_client.h b/chromeos/dbus/fake_bluetooth_adapter_client.h
index 6eb994a..051368f 100644
--- a/chromeos/dbus/fake_bluetooth_adapter_client.h
+++ b/chromeos/dbus/fake_bluetooth_adapter_client.h
@@ -39,7 +39,8 @@ class CHROMEOS_EXPORT FakeBluetoothAdapterClient
   FakeBluetoothAdapterClient();
   virtual ~FakeBluetoothAdapterClient();
 
-  // BluetoothAdapterClient override
+  // BluetoothAdapterClient overrides
+  virtual void Init(dbus::Bus* bus) OVERRIDE;
   virtual void AddObserver(Observer* observer) OVERRIDE;
   virtual void RemoveObserver(Observer* observer) OVERRIDE;
   virtual std::vector<dbus::ObjectPath> GetAdapters() OVERRIDE;
diff --git a/chromeos/dbus/fake_bluetooth_agent_manager_client.cc b/chromeos/dbus/fake_bluetooth_agent_manager_client.cc
index 57759ff..2672ad5 100644
--- a/chromeos/dbus/fake_bluetooth_agent_manager_client.cc
+++ b/chromeos/dbus/fake_bluetooth_agent_manager_client.cc
@@ -19,6 +19,9 @@ FakeBluetoothAgentManagerClient::FakeBluetoothAgentManagerClient()
 FakeBluetoothAgentManagerClient::~FakeBluetoothAgentManagerClient() {
 }
 
+void FakeBluetoothAgentManagerClient::Init(dbus::Bus* bus) {
+}
+
 void FakeBluetoothAgentManagerClient::RegisterAgent(
     const dbus::ObjectPath& agent_path,
     const std::string& capability,
diff --git a/chromeos/dbus/fake_bluetooth_agent_manager_client.h b/chromeos/dbus/fake_bluetooth_agent_manager_client.h
index 315fd5e..98ecdb2 100644
--- a/chromeos/dbus/fake_bluetooth_agent_manager_client.h
+++ b/chromeos/dbus/fake_bluetooth_agent_manager_client.h
@@ -27,7 +27,8 @@ class CHROMEOS_EXPORT FakeBluetoothAgentManagerClient
   FakeBluetoothAgentManagerClient();
   virtual ~FakeBluetoothAgentManagerClient();
 
-  // BluetoothAgentManagerClient override
+  // BluetoothAgentManagerClient overrides
+  virtual void Init(dbus::Bus* bus) OVERRIDE;
   virtual void RegisterAgent(const dbus::ObjectPath& agent_path,
                              const std::string& capability,
                              const base::Closure& callback,
diff --git a/chromeos/dbus/fake_bluetooth_device_client.cc b/chromeos/dbus/fake_bluetooth_device_client.cc
index 4146163..08f748a 100644
--- a/chromeos/dbus/fake_bluetooth_device_client.cc
+++ b/chromeos/dbus/fake_bluetooth_device_client.cc
@@ -62,7 +62,7 @@ void SimulatedProfileSocket(int fd) {
   close(fd);
 }
 
-}
+}  // namespace
 
 namespace chromeos {
 
@@ -188,7 +188,6 @@ void FakeBluetoothDeviceClient::Properties::Set(
   }
 }
 
-
 FakeBluetoothDeviceClient::FakeBluetoothDeviceClient()
     : simulation_interval_ms_(kSimulationIntervalMs),
       discovery_simulation_step_(0),
@@ -222,6 +221,9 @@ FakeBluetoothDeviceClient::~FakeBluetoothDeviceClient() {
   STLDeleteValues(&properties_map_);
 }
 
+void FakeBluetoothDeviceClient::Init(dbus::Bus* bus) {
+}
+
 void FakeBluetoothDeviceClient::AddObserver(Observer* observer) {
   observers_.AddObserver(observer);
 }
diff --git a/chromeos/dbus/fake_bluetooth_device_client.h b/chromeos/dbus/fake_bluetooth_device_client.h
index e5cfc51..ccb68b7 100644
--- a/chromeos/dbus/fake_bluetooth_device_client.h
+++ b/chromeos/dbus/fake_bluetooth_device_client.h
@@ -42,7 +42,8 @@ class CHROMEOS_EXPORT FakeBluetoothDeviceClient
   FakeBluetoothDeviceClient();
   virtual ~FakeBluetoothDeviceClient();
 
-  // BluetoothDeviceClient override
+  // BluetoothDeviceClient overrides
+  virtual void Init(dbus::Bus* bus) OVERRIDE;
   virtual void AddObserver(Observer* observer) OVERRIDE;
   virtual void RemoveObserver(Observer* observer) OVERRIDE;
   virtual std::vector<dbus::ObjectPath> GetDevicesForAdapter(
diff --git a/chromeos/dbus/fake_bluetooth_input_client.cc b/chromeos/dbus/fake_bluetooth_input_client.cc
index 717df07..9e40f6e 100644
--- a/chromeos/dbus/fake_bluetooth_input_client.cc
+++ b/chromeos/dbus/fake_bluetooth_input_client.cc
@@ -56,6 +56,9 @@ FakeBluetoothInputClient::~FakeBluetoothInputClient() {
   STLDeleteValues(&properties_map_);
 }
 
+void FakeBluetoothInputClient::Init(dbus::Bus* bus) {
+}
+
 void FakeBluetoothInputClient::AddObserver(Observer* observer) {
   observers_.AddObserver(observer);
 }
diff --git a/chromeos/dbus/fake_bluetooth_input_client.h b/chromeos/dbus/fake_bluetooth_input_client.h
index 8152668..3a284ae 100644
--- a/chromeos/dbus/fake_bluetooth_input_client.h
+++ b/chromeos/dbus/fake_bluetooth_input_client.h
@@ -36,7 +36,8 @@ class CHROMEOS_EXPORT FakeBluetoothInputClient
   FakeBluetoothInputClient();
   virtual ~FakeBluetoothInputClient();
 
-  // BluetoothInputClient override
+  // BluetoothInputClient overrides
+  virtual void Init(dbus::Bus* bus) OVERRIDE;
   virtual void AddObserver(Observer* observer) OVERRIDE;
   virtual void RemoveObserver(Observer* observer) OVERRIDE;
   virtual Properties* GetProperties(const dbus::ObjectPath& object_path)
diff --git a/chromeos/dbus/fake_bluetooth_profile_manager_client.cc b/chromeos/dbus/fake_bluetooth_profile_manager_client.cc
index 4c7e0a4..784a84f 100644
--- a/chromeos/dbus/fake_bluetooth_profile_manager_client.cc
+++ b/chromeos/dbus/fake_bluetooth_profile_manager_client.cc
@@ -29,6 +29,9 @@ FakeBluetoothProfileManagerClient::FakeBluetoothProfileManagerClient() {
 FakeBluetoothProfileManagerClient::~FakeBluetoothProfileManagerClient() {
 }
 
+void FakeBluetoothProfileManagerClient::Init(dbus::Bus* bus) {
+}
+
 void FakeBluetoothProfileManagerClient::RegisterProfile(
     const dbus::ObjectPath& profile_path,
     const std::string& uuid,
diff --git a/chromeos/dbus/fake_bluetooth_profile_manager_client.h b/chromeos/dbus/fake_bluetooth_profile_manager_client.h
index 8bfeaaf..c7fb935 100644
--- a/chromeos/dbus/fake_bluetooth_profile_manager_client.h
+++ b/chromeos/dbus/fake_bluetooth_profile_manager_client.h
@@ -30,7 +30,8 @@ class CHROMEOS_EXPORT FakeBluetoothProfileManagerClient
   FakeBluetoothProfileManagerClient();
   virtual ~FakeBluetoothProfileManagerClient();
 
-  // BluetoothProfileManagerClient override
+  // BluetoothProfileManagerClient overrides
+  virtual void Init(dbus::Bus* bus) OVERRIDE;
   virtual void RegisterProfile(const dbus::ObjectPath& profile_path,
                                const std::string& uuid,
                                const Options& options,
diff --git a/chromeos/dbus/fake_cros_disks_client.cc b/chromeos/dbus/fake_cros_disks_client.cc
index 30c89b0..b152f72 100644
--- a/chromeos/dbus/fake_cros_disks_client.cc
+++ b/chromeos/dbus/fake_cros_disks_client.cc
@@ -10,13 +10,17 @@
 namespace chromeos {
 
 FakeCrosDisksClient::FakeCrosDisksClient()
-  : unmount_call_count_(0),
-    unmount_success_(true),
-    format_device_call_count_(0),
-    format_device_success_(true) {
+    : unmount_call_count_(0),
+      unmount_success_(true),
+      format_device_call_count_(0),
+      format_device_success_(true) {
 }
 
-FakeCrosDisksClient::~FakeCrosDisksClient() {}
+FakeCrosDisksClient::~FakeCrosDisksClient() {
+}
+
+void FakeCrosDisksClient::Init(dbus::Bus* bus) {
+}
 
 void FakeCrosDisksClient::Mount(const std::string& source_path,
                                 const std::string& source_format,
@@ -37,7 +41,7 @@ void FakeCrosDisksClient::Unmount(const std::string& device_path,
   last_unmount_options_ = options;
   base::MessageLoopProxy::current()->PostTask(
       FROM_HERE, unmount_success_ ? callback : error_callback);
-  if(!unmount_listener_.is_null())
+  if (!unmount_listener_.is_null())
     unmount_listener_.Run();
 }
 
diff --git a/chromeos/dbus/fake_cros_disks_client.h b/chromeos/dbus/fake_cros_disks_client.h
index 49e8fba..855a3c1 100644
--- a/chromeos/dbus/fake_cros_disks_client.h
+++ b/chromeos/dbus/fake_cros_disks_client.h
@@ -19,7 +19,8 @@ class FakeCrosDisksClient : public CrosDisksClient {
   FakeCrosDisksClient();
   virtual ~FakeCrosDisksClient();
 
-  // CrosDisksClient overrides.
+  // CrosDisksClient overrides
+  virtual void Init(dbus::Bus* bus) OVERRIDE;
   virtual void Mount(const std::string& source_path,
                      const std::string& source_format,
                      const std::string& mount_label,
diff --git a/chromeos/dbus/fake_cryptohome_client.cc b/chromeos/dbus/fake_cryptohome_client.cc
index c5df786..1d224d9 100644
--- a/chromeos/dbus/fake_cryptohome_client.cc
+++ b/chromeos/dbus/fake_cryptohome_client.cc
@@ -23,6 +23,9 @@ FakeCryptohomeClient::FakeCryptohomeClient() : unmount_result_(false) {
 FakeCryptohomeClient::~FakeCryptohomeClient() {
 }
 
+void FakeCryptohomeClient::Init(dbus::Bus* bus) {
+}
+
 void FakeCryptohomeClient::TpmIsBeingOwned(
     const BoolDBusMethodCallback& callback) {
 }
diff --git a/chromeos/dbus/fake_cryptohome_client.h b/chromeos/dbus/fake_cryptohome_client.h
index e254648..74d9e81 100644
--- a/chromeos/dbus/fake_cryptohome_client.h
+++ b/chromeos/dbus/fake_cryptohome_client.h
@@ -18,7 +18,8 @@ class FakeCryptohomeClient : public CryptohomeClient {
   FakeCryptohomeClient();
   virtual ~FakeCryptohomeClient();
 
-  // CryptohomeClient overrides.
+  // CryptohomeClient overrides
+  virtual void Init(dbus::Bus* bus) OVERRIDE;
   virtual void SetAsyncCallStatusHandlers(
       const AsyncCallStatusHandler& handler,
       const AsyncCallStatusWithDataHandler& data_handler) OVERRIDE;
diff --git a/chromeos/dbus/fake_gsm_sms_client.cc b/chromeos/dbus/fake_gsm_sms_client.cc
index d1904d7..4d4452f 100644
--- a/chromeos/dbus/fake_gsm_sms_client.cc
+++ b/chromeos/dbus/fake_gsm_sms_client.cc
@@ -9,9 +9,9 @@
 namespace chromeos {
 
 FakeGsmSMSClient::FakeGsmSMSClient()
-  : test_index_(-1),
-    sms_test_message_switch_present_(false),
-    weak_ptr_factory_(this)  {
+    : test_index_(-1),
+      sms_test_message_switch_present_(false),
+      weak_ptr_factory_(this) {
   test_messages_.push_back("Test Message 0");
   test_messages_.push_back("Test Message 1");
   test_messages_.push_back("Test a relatively long message 2");
@@ -22,7 +22,11 @@ FakeGsmSMSClient::FakeGsmSMSClient()
   test_messages_.push_back("Test Message 6");
 }
 
-FakeGsmSMSClient::~FakeGsmSMSClient() {}
+FakeGsmSMSClient::~FakeGsmSMSClient() {
+}
+
+void FakeGsmSMSClient::Init(dbus::Bus* bus) {
+}
 
 void FakeGsmSMSClient::SetSmsReceivedHandler(
     const std::string& service_name,
diff --git a/chromeos/dbus/fake_gsm_sms_client.h b/chromeos/dbus/fake_gsm_sms_client.h
index 1a846ee..321c9f6 100644
--- a/chromeos/dbus/fake_gsm_sms_client.h
+++ b/chromeos/dbus/fake_gsm_sms_client.h
@@ -20,7 +20,8 @@ class FakeGsmSMSClient : public GsmSMSClient {
   FakeGsmSMSClient();
   virtual ~FakeGsmSMSClient();
 
-  // GsmSMSClient overrides.
+  // GsmSMSClient overrides
+  virtual void Init(dbus::Bus* bus) OVERRIDE;
   virtual void SetSmsReceivedHandler(const std::string& service_name,
                                      const dbus::ObjectPath& object_path,
                                      const SmsReceivedHandler& handler)
diff --git a/chromeos/dbus/fake_image_burner_client.cc b/chromeos/dbus/fake_image_burner_client.cc
index 978687e..01683b5 100644
--- a/chromeos/dbus/fake_image_burner_client.cc
+++ b/chromeos/dbus/fake_image_burner_client.cc
@@ -12,6 +12,9 @@ FakeImageBurnerClient::FakeImageBurnerClient() {
 FakeImageBurnerClient::~FakeImageBurnerClient() {
 }
 
+void FakeImageBurnerClient::Init(dbus::Bus* bus) {
+}
+
 void FakeImageBurnerClient::ResetEventHandlers() {
 }
 
diff --git a/chromeos/dbus/fake_image_burner_client.h b/chromeos/dbus/fake_image_burner_client.h
index cb18bcf..b730ad2 100644
--- a/chromeos/dbus/fake_image_burner_client.h
+++ b/chromeos/dbus/fake_image_burner_client.h
@@ -17,7 +17,8 @@ class FakeImageBurnerClient : public ImageBurnerClient {
   FakeImageBurnerClient();
   virtual ~FakeImageBurnerClient();
 
-  // ImageBurnerClient overrides.
+  // ImageBurnerClient overrides
+  virtual void Init(dbus::Bus* bus) OVERRIDE;
   virtual void BurnImage(const std::string& from_path,
                          const std::string& to_path,
                          const ErrorCallback& error_callback) OVERRIDE;
diff --git a/chromeos/dbus/fake_power_manager_client.cc b/chromeos/dbus/fake_power_manager_client.cc
index 3fda910..a0762ef 100644
--- a/chromeos/dbus/fake_power_manager_client.cc
+++ b/chromeos/dbus/fake_power_manager_client.cc
@@ -8,12 +8,15 @@
 namespace chromeos {
 
 FakePowerManagerClient::FakePowerManagerClient()
-  : request_restart_call_count_(0) {
+    : request_restart_call_count_(0) {
 }
 
 FakePowerManagerClient::~FakePowerManagerClient() {
 }
 
+void FakePowerManagerClient::Init(dbus::Bus* bus) {
+}
+
 void FakePowerManagerClient::AddObserver(Observer* observer) {
 }
 
diff --git a/chromeos/dbus/fake_power_manager_client.h b/chromeos/dbus/fake_power_manager_client.h
index 31dd227..001d783 100644
--- a/chromeos/dbus/fake_power_manager_client.h
+++ b/chromeos/dbus/fake_power_manager_client.h
@@ -20,7 +20,8 @@ class FakePowerManagerClient : public PowerManagerClient {
   FakePowerManagerClient();
   virtual ~FakePowerManagerClient();
 
-  // PowerManagerClient overrides.
+  // PowerManagerClient overrides
+  virtual void Init(dbus::Bus* bus) OVERRIDE;
   virtual void AddObserver(Observer* observer) OVERRIDE;
   virtual void RemoveObserver(Observer* observer) OVERRIDE;
   virtual bool HasObserver(Observer* observer) OVERRIDE;
diff --git a/chromeos/dbus/fake_session_manager_client.cc b/chromeos/dbus/fake_session_manager_client.cc
index 37d90da..b384a03 100644
--- a/chromeos/dbus/fake_session_manager_client.cc
+++ b/chromeos/dbus/fake_session_manager_client.cc
@@ -13,14 +13,17 @@
 namespace chromeos {
 
 FakeSessionManagerClient::FakeSessionManagerClient()
-  : emit_login_prompt_ready_call_count_(0) ,
-    notify_lock_screen_shown_call_count_(0),
-    notify_lock_screen_dismissed_call_count_(0){
+    : emit_login_prompt_ready_call_count_(0),
+      notify_lock_screen_shown_call_count_(0),
+      notify_lock_screen_dismissed_call_count_(0) {
 }
 
 FakeSessionManagerClient::~FakeSessionManagerClient() {
 }
 
+void FakeSessionManagerClient::Init(dbus::Bus* bus) {
+}
+
 void FakeSessionManagerClient::AddObserver(Observer* observer) {
   observers_.AddObserver(observer);
 }
diff --git a/chromeos/dbus/fake_session_manager_client.h b/chromeos/dbus/fake_session_manager_client.h
index 5c8941b3..993a071 100644
--- a/chromeos/dbus/fake_session_manager_client.h
+++ b/chromeos/dbus/fake_session_manager_client.h
@@ -17,12 +17,13 @@ namespace chromeos {
 
 // A fake implementation of session_manager. Accepts policy blobs to be set and
 // returns them unmodified.
-class FakeSessionManagerClient : public chromeos::SessionManagerClient {
+class FakeSessionManagerClient : public SessionManagerClient {
  public:
   FakeSessionManagerClient();
   virtual ~FakeSessionManagerClient();
 
-  // SessionManagerClient:
+  // SessionManagerClient overrides
+  virtual void Init(dbus::Bus* bus) OVERRIDE;
   virtual void AddObserver(Observer* observer) OVERRIDE;
   virtual void RemoveObserver(Observer* observer) OVERRIDE;
   virtual bool HasObserver(Observer* observer) OVERRIDE;
diff --git a/chromeos/dbus/fake_shill_device_client.cc b/chromeos/dbus/fake_shill_device_client.cc
index 4d8c7f3..2bf0b65 100644
--- a/chromeos/dbus/fake_shill_device_client.cc
+++ b/chromeos/dbus/fake_shill_device_client.cc
@@ -12,6 +12,9 @@ FakeShillDeviceClient::FakeShillDeviceClient() {
 FakeShillDeviceClient::~FakeShillDeviceClient() {
 }
 
+void FakeShillDeviceClient::Init(dbus::Bus* bus) {
+}
+
 void FakeShillDeviceClient::AddPropertyChangedObserver(
     const dbus::ObjectPath& device_path,
     ShillPropertyChangedObserver* observer) {
diff --git a/chromeos/dbus/fake_shill_device_client.h b/chromeos/dbus/fake_shill_device_client.h
index b887bb7..c97bae1 100644
--- a/chromeos/dbus/fake_shill_device_client.h
+++ b/chromeos/dbus/fake_shill_device_client.h
@@ -18,7 +18,8 @@ class FakeShillDeviceClient : public ShillDeviceClient {
   FakeShillDeviceClient();
   virtual ~FakeShillDeviceClient();
 
-  // ShillDeviceClient overrides.
+  // ShillDeviceClient overrides
+  virtual void Init(dbus::Bus* bus) OVERRIDE;
   virtual void AddPropertyChangedObserver(
       const dbus::ObjectPath& device_path,
       ShillPropertyChangedObserver* observer) OVERRIDE;
diff --git a/chromeos/dbus/fake_shill_manager_client.cc b/chromeos/dbus/fake_shill_manager_client.cc
index 35b256a..faab3d5 100644
--- a/chromeos/dbus/fake_shill_manager_client.cc
+++ b/chromeos/dbus/fake_shill_manager_client.cc
@@ -12,6 +12,9 @@ FakeShillManagerClient::FakeShillManagerClient() {
 FakeShillManagerClient::~FakeShillManagerClient() {
 }
 
+void FakeShillManagerClient::Init(dbus::Bus* bus) {
+}
+
 void FakeShillManagerClient::RequestScan(const std::string& type,
                                          const base::Closure& callback,
                                          const ErrorCallback& error_callback) {
diff --git a/chromeos/dbus/fake_shill_manager_client.h b/chromeos/dbus/fake_shill_manager_client.h
index 2a1c0e72..1d1ba1a 100644
--- a/chromeos/dbus/fake_shill_manager_client.h
+++ b/chromeos/dbus/fake_shill_manager_client.h
@@ -17,7 +17,8 @@ class FakeShillManagerClient : public ShillManagerClient {
   FakeShillManagerClient();
   virtual ~FakeShillManagerClient();
 
-  // ShillManagerClient overrides.
+  // ShillManagerClient overrides
+  virtual void Init(dbus::Bus* bus) OVERRIDE;
   virtual void AddPropertyChangedObserver(
       ShillPropertyChangedObserver* observer) OVERRIDE;
   virtual void RemovePropertyChangedObserver(
diff --git a/chromeos/dbus/fake_system_clock_client.cc b/chromeos/dbus/fake_system_clock_client.cc
index ea1b737..92a8dd3 100644
--- a/chromeos/dbus/fake_system_clock_client.cc
+++ b/chromeos/dbus/fake_system_clock_client.cc
@@ -12,6 +12,9 @@ FakeSystemClockClient::FakeSystemClockClient() {
 FakeSystemClockClient::~FakeSystemClockClient() {
 }
 
+void FakeSystemClockClient::Init(dbus::Bus* bus) {
+}
+
 void FakeSystemClockClient::AddObserver(Observer* observer) {
 }
 
diff --git a/chromeos/dbus/fake_system_clock_client.h b/chromeos/dbus/fake_system_clock_client.h
index cea91a6..31a3ebc 100644
--- a/chromeos/dbus/fake_system_clock_client.h
+++ b/chromeos/dbus/fake_system_clock_client.h
@@ -15,7 +15,8 @@ class FakeSystemClockClient : public SystemClockClient {
   FakeSystemClockClient();
   virtual ~FakeSystemClockClient();
 
-  // SystemClockClient overrides.
+  // SystemClockClient overrides
+  virtual void Init(dbus::Bus* bus) OVERRIDE;
   virtual void AddObserver(Observer* observer) OVERRIDE;
   virtual void RemoveObserver(Observer* observer) OVERRIDE;
   virtual bool HasObserver(Observer* observer) OVERRIDE;
diff --git a/chromeos/dbus/fake_update_engine_client.cc b/chromeos/dbus/fake_update_engine_client.cc
index b9f40a2..a246c41 100644
--- a/chromeos/dbus/fake_update_engine_client.cc
+++ b/chromeos/dbus/fake_update_engine_client.cc
@@ -7,13 +7,16 @@
 namespace chromeos {
 
 FakeUpdateEngineClient::FakeUpdateEngineClient()
-  : update_check_result_(UpdateEngineClient::UPDATE_RESULT_SUCCESS),
-    reboot_after_update_call_count_(0) {
+    : update_check_result_(UpdateEngineClient::UPDATE_RESULT_SUCCESS),
+      reboot_after_update_call_count_(0) {
 }
 
 FakeUpdateEngineClient::~FakeUpdateEngineClient() {
 }
 
+void FakeUpdateEngineClient::Init(dbus::Bus* bus) {
+}
+
 void FakeUpdateEngineClient::AddObserver(Observer* observer) {
 }
 
diff --git a/chromeos/dbus/fake_update_engine_client.h b/chromeos/dbus/fake_update_engine_client.h
index 605d161..c5afe18 100644
--- a/chromeos/dbus/fake_update_engine_client.h
+++ b/chromeos/dbus/fake_update_engine_client.h
@@ -21,7 +21,8 @@ class FakeUpdateEngineClient : public UpdateEngineClient {
   FakeUpdateEngineClient();
   virtual ~FakeUpdateEngineClient();
 
-  // Overrides
+  // UpdateEngineClient overrides
+  virtual void Init(dbus::Bus* bus) OVERRIDE;
   virtual void AddObserver(Observer* observer) OVERRIDE;
   virtual void RemoveObserver(Observer* observer) OVERRIDE;
   virtual bool HasObserver(Observer* observer) OVERRIDE;
diff --git a/chromeos/dbus/gsm_sms_client.cc b/chromeos/dbus/gsm_sms_client.cc
index ae9b900..4fead8d 100644
--- a/chromeos/dbus/gsm_sms_client.cc
+++ b/chromeos/dbus/gsm_sms_client.cc
@@ -165,10 +165,7 @@ class SMSProxy {
 // The GsmSMSClient implementation.
 class GsmSMSClientImpl : public GsmSMSClient {
  public:
-  explicit GsmSMSClientImpl(dbus::Bus* bus)
-      : bus_(bus),
-        proxies_deleter_(&proxies_) {
-  }
+  GsmSMSClientImpl() : bus_(NULL), proxies_deleter_(&proxies_) {}
 
   // GsmSMSClient override.
   virtual void SetSmsReceivedHandler(
@@ -213,6 +210,9 @@ class GsmSMSClientImpl : public GsmSMSClient {
                              const dbus::ObjectPath& object_path) OVERRIDE {
   }
 
+ protected:
+  virtual void Init(dbus::Bus* bus) OVERRIDE { bus_ = bus; }
+
  private:
   typedef std::map<std::pair<std::string, std::string>, SMSProxy*> ProxyMap;
 
@@ -247,10 +247,9 @@ GsmSMSClient::GsmSMSClient() {}
 GsmSMSClient::~GsmSMSClient() {}
 
 // static
-GsmSMSClient* GsmSMSClient::Create(DBusClientImplementationType type,
-                                   dbus::Bus* bus) {
+GsmSMSClient* GsmSMSClient::Create(DBusClientImplementationType type) {
   if (type == REAL_DBUS_CLIENT_IMPLEMENTATION)
-    return new GsmSMSClientImpl(bus);
+    return new GsmSMSClientImpl();
   DCHECK_EQ(STUB_DBUS_CLIENT_IMPLEMENTATION, type);
 
   FakeGsmSMSClient* fake = new FakeGsmSMSClient();
diff --git a/chromeos/dbus/gsm_sms_client.h b/chromeos/dbus/gsm_sms_client.h
index 4effeff..af30753 100644
--- a/chromeos/dbus/gsm_sms_client.h
+++ b/chromeos/dbus/gsm_sms_client.h
@@ -10,6 +10,7 @@
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "chromeos/chromeos_export.h"
+#include "chromeos/dbus/dbus_client.h"
 #include "chromeos/dbus/dbus_client_implementation_type.h"
 
 namespace base {
@@ -18,7 +19,6 @@ class ListValue;
 }
 
 namespace dbus {
-class Bus;
 class ObjectPath;
 }
 
@@ -28,7 +28,7 @@ namespace chromeos {
 // org.freedesktop.ModemManager.Modem.Gsm.SMS service.
 // All methods should be called from the origin thread (UI thread) which
 // initializes the DBusThreadManager instance.
-class CHROMEOS_EXPORT GsmSMSClient {
+class CHROMEOS_EXPORT GsmSMSClient : public DBusClient {
  public:
   typedef base::Callback<void(uint32 index, bool complete)> SmsReceivedHandler;
   typedef base::Callback<void()> DeleteCallback;
@@ -39,8 +39,7 @@ class CHROMEOS_EXPORT GsmSMSClient {
 
   // Factory function, creates a new instance and returns ownership.
   // For normal usage, access the singleton via DBusThreadManager::Get().
-  static GsmSMSClient* Create(DBusClientImplementationType type,
-                              dbus::Bus* bus);
+  static GsmSMSClient* Create(DBusClientImplementationType type);
 
   // Sets SmsReceived signal handler.
   virtual void SetSmsReceivedHandler(const std::string& service_name,
@@ -74,6 +73,8 @@ class CHROMEOS_EXPORT GsmSMSClient {
                              const dbus::ObjectPath& object_path) = 0;
 
  protected:
+  friend class GsmSMSClientTest;
+
   // Create() should be used instead.
   GsmSMSClient();
 
diff --git a/chromeos/dbus/gsm_sms_client_unittest.cc b/chromeos/dbus/gsm_sms_client_unittest.cc
index baed2f7..8a956c4 100644
--- a/chromeos/dbus/gsm_sms_client_unittest.cc
+++ b/chromeos/dbus/gsm_sms_client_unittest.cc
@@ -99,8 +99,8 @@ class GsmSMSClientTest : public testing::Test {
     EXPECT_CALL(*mock_bus_.get(), ShutdownAndBlock()).WillOnce(Return());
 
     // Create a client with the mock bus.
-    client_.reset(
-        GsmSMSClient::Create(REAL_DBUS_CLIENT_IMPLEMENTATION, mock_bus_.get()));
+    client_.reset(GsmSMSClient::Create(REAL_DBUS_CLIENT_IMPLEMENTATION));
+    client_->Init(mock_bus_.get());
   }
 
   virtual void TearDown() OVERRIDE {
diff --git a/chromeos/dbus/image_burner_client.cc b/chromeos/dbus/image_burner_client.cc
index 86c4249a8..a807f07 100644
--- a/chromeos/dbus/image_burner_client.cc
+++ b/chromeos/dbus/image_burner_client.cc
@@ -20,27 +20,8 @@ namespace {
 // The ImageBurnerClient implementation.
 class ImageBurnerClientImpl : public ImageBurnerClient {
  public:
-  explicit ImageBurnerClientImpl(dbus::Bus* bus)
-      : proxy_(NULL),
-        weak_ptr_factory_(this) {
-    proxy_ = bus->GetObjectProxy(
-        imageburn::kImageBurnServiceName,
-        dbus::ObjectPath(imageburn::kImageBurnServicePath));
-    proxy_->ConnectToSignal(
-        imageburn::kImageBurnServiceInterface,
-        imageburn::kSignalBurnFinishedName,
-        base::Bind(&ImageBurnerClientImpl::OnBurnFinished,
-                   weak_ptr_factory_.GetWeakPtr()),
-        base::Bind(&ImageBurnerClientImpl::OnSignalConnected,
-                   weak_ptr_factory_.GetWeakPtr()));
-    proxy_->ConnectToSignal(
-        imageburn::kImageBurnServiceInterface,
-        imageburn::kSignalBurnUpdateName,
-        base::Bind(&ImageBurnerClientImpl::OnBurnProgressUpdate,
-                   weak_ptr_factory_.GetWeakPtr()),
-        base::Bind(&ImageBurnerClientImpl::OnSignalConnected,
-                   weak_ptr_factory_.GetWeakPtr()));
-  }
+  ImageBurnerClientImpl() : proxy_(NULL), weak_ptr_factory_(this) {}
+
   virtual ~ImageBurnerClientImpl() {}
 
   // ImageBurnerClient override.
@@ -72,6 +53,27 @@ class ImageBurnerClientImpl : public ImageBurnerClient {
     burn_progress_update_handler_.Reset();
   }
 
+ protected:
+  virtual void Init(dbus::Bus* bus) OVERRIDE {
+    proxy_ =
+        bus->GetObjectProxy(imageburn::kImageBurnServiceName,
+                            dbus::ObjectPath(imageburn::kImageBurnServicePath));
+    proxy_->ConnectToSignal(
+        imageburn::kImageBurnServiceInterface,
+        imageburn::kSignalBurnFinishedName,
+        base::Bind(&ImageBurnerClientImpl::OnBurnFinished,
+                   weak_ptr_factory_.GetWeakPtr()),
+        base::Bind(&ImageBurnerClientImpl::OnSignalConnected,
+                   weak_ptr_factory_.GetWeakPtr()));
+    proxy_->ConnectToSignal(
+        imageburn::kImageBurnServiceInterface,
+        imageburn::kSignalBurnUpdateName,
+        base::Bind(&ImageBurnerClientImpl::OnBurnProgressUpdate,
+                   weak_ptr_factory_.GetWeakPtr()),
+        base::Bind(&ImageBurnerClientImpl::OnSignalConnected,
+                   weak_ptr_factory_.GetWeakPtr()));
+  }
+
  private:
   // Called when a response for BurnImage is received
   void OnBurnImage(ErrorCallback error_callback, dbus::Response* response) {
@@ -142,10 +144,10 @@ ImageBurnerClient::~ImageBurnerClient() {
 }
 
 // static
-ImageBurnerClient* ImageBurnerClient::Create(DBusClientImplementationType type,
-                                             dbus::Bus* bus) {
+ImageBurnerClient* ImageBurnerClient::Create(
+    DBusClientImplementationType type) {
   if (type == REAL_DBUS_CLIENT_IMPLEMENTATION)
-    return new ImageBurnerClientImpl(bus);
+    return new ImageBurnerClientImpl();
   DCHECK_EQ(STUB_DBUS_CLIENT_IMPLEMENTATION, type);
   return new FakeImageBurnerClient();
 }
diff --git a/chromeos/dbus/image_burner_client.h b/chromeos/dbus/image_burner_client.h
index 053b430..c6f65ef 100644
--- a/chromeos/dbus/image_burner_client.h
+++ b/chromeos/dbus/image_burner_client.h
@@ -10,18 +10,15 @@
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "chromeos/chromeos_export.h"
+#include "chromeos/dbus/dbus_client.h"
 #include "chromeos/dbus/dbus_client_implementation_type.h"
 
-namespace dbus {
-class Bus;
-}
-
 namespace chromeos {
 
 // ImageBurnerClient is used to communicate with the image burner.
 // All method should be called from the origin thread (UI thread) which
 // initializes the DBusThreadManager instance.
-class CHROMEOS_EXPORT ImageBurnerClient {
+class CHROMEOS_EXPORT ImageBurnerClient : public DBusClient {
  public:
   virtual ~ImageBurnerClient();
 
@@ -57,8 +54,7 @@ class CHROMEOS_EXPORT ImageBurnerClient {
 
   // Factory function, creates a new instance and returns ownership.
   // For normal usage, access the singleton via DBusThreadManager::Get().
-  static ImageBurnerClient* Create(DBusClientImplementationType type,
-                                   dbus::Bus* bus);
+  static ImageBurnerClient* Create(DBusClientImplementationType type);
 
  protected:
   // Create() should be used instead.
diff --git a/chromeos/dbus/introspectable_client.cc b/chromeos/dbus/introspectable_client.cc
index 83b09a3..81cc8a1 100644
--- a/chromeos/dbus/introspectable_client.cc
+++ b/chromeos/dbus/introspectable_client.cc
@@ -32,10 +32,7 @@ namespace chromeos {
 // The IntrospectableClient implementation used in production.
 class IntrospectableClientImpl : public IntrospectableClient {
  public:
-  explicit IntrospectableClientImpl(dbus::Bus* bus)
-      : bus_(bus),
-        weak_ptr_factory_(this) {
-  }
+  IntrospectableClientImpl() : bus_(NULL), weak_ptr_factory_(this) {}
 
   virtual ~IntrospectableClientImpl() {
   }
@@ -57,6 +54,9 @@ class IntrospectableClientImpl : public IntrospectableClient {
                    service_name, object_path, callback));
   }
 
+ protected:
+  virtual void Init(dbus::Bus* bus) OVERRIDE { bus_ = bus; }
+
  private:
   // Called by dbus:: when a response for Introspect() is recieved.
   void OnIntrospect(const std::string& service_name,
@@ -96,6 +96,7 @@ class IntrospectableClientImpl : public IntrospectableClient {
 class IntrospectableClientStubImpl : public IntrospectableClient {
  public:
   // IntrospectableClient override.
+  virtual void Init(dbus::Bus* bus) OVERRIDE {}
   virtual void Introspect(const std::string& service_name,
                           const dbus::ObjectPath& object_path,
                           const IntrospectCallback& callback) OVERRIDE {
@@ -145,10 +146,9 @@ IntrospectableClient::GetInterfacesFromIntrospectResult(
 
 // static
 IntrospectableClient* IntrospectableClient::Create(
-    DBusClientImplementationType type,
-    dbus::Bus* bus) {
+    DBusClientImplementationType type) {
   if (type == REAL_DBUS_CLIENT_IMPLEMENTATION)
-    return new IntrospectableClientImpl(bus);
+    return new IntrospectableClientImpl();
   DCHECK_EQ(STUB_DBUS_CLIENT_IMPLEMENTATION, type);
   return new IntrospectableClientStubImpl();
 }
diff --git a/chromeos/dbus/introspectable_client.h b/chromeos/dbus/introspectable_client.h
index 1ee15d6..573b9f9 100644
--- a/chromeos/dbus/introspectable_client.h
+++ b/chromeos/dbus/introspectable_client.h
@@ -10,18 +10,15 @@
 
 #include "base/callback.h"
 #include "chromeos/chromeos_export.h"
+#include "chromeos/dbus/dbus_client.h"
 #include "chromeos/dbus/dbus_client_implementation_type.h"
 #include "dbus/object_path.h"
 
-namespace dbus {
-class Bus;
-}  // namespace dbus
-
 namespace chromeos {
 
 // IntrospectableClient is used to retrieve the D-Bus introspection data
 // from a remote object.
-class CHROMEOS_EXPORT IntrospectableClient {
+class CHROMEOS_EXPORT IntrospectableClient : public DBusClient {
  public:
   virtual ~IntrospectableClient();
 
@@ -48,8 +45,7 @@ class CHROMEOS_EXPORT IntrospectableClient {
       const std::string& xml_data);
 
   // Creates the instance
-  static IntrospectableClient* Create(DBusClientImplementationType type,
-                                      dbus::Bus* bus);
+  static IntrospectableClient* Create(DBusClientImplementationType type);
 
  protected:
   IntrospectableClient();
diff --git a/chromeos/dbus/mock_cryptohome_client.h b/chromeos/dbus/mock_cryptohome_client.h
index 86986e6..f057709 100644
--- a/chromeos/dbus/mock_cryptohome_client.h
+++ b/chromeos/dbus/mock_cryptohome_client.h
@@ -17,6 +17,7 @@ class MockCryptohomeClient : public CryptohomeClient {
   MockCryptohomeClient();
   virtual ~MockCryptohomeClient();
 
+  MOCK_METHOD1(Init, void(dbus::Bus* bus));
   MOCK_METHOD2(SetAsyncCallStatusHandlers,
                void(const AsyncCallStatusHandler& handler,
                     const AsyncCallStatusWithDataHandler& data_handler));
diff --git a/chromeos/dbus/mock_gsm_sms_client.h b/chromeos/dbus/mock_gsm_sms_client.h
index bc0bee9..aa522c5 100644
--- a/chromeos/dbus/mock_gsm_sms_client.h
+++ b/chromeos/dbus/mock_gsm_sms_client.h
@@ -19,6 +19,7 @@ class MockGsmSMSClient : public GsmSMSClient {
   MockGsmSMSClient();
   virtual ~MockGsmSMSClient();
 
+  MOCK_METHOD1(Init, void(dbus::Bus* bus));
   MOCK_METHOD3(SetSmsReceivedHandler, void(const std::string& service_name,
                                            const dbus::ObjectPath& object_path,
                                            const SmsReceivedHandler& handler));
diff --git a/chromeos/dbus/mock_session_manager_client.h b/chromeos/dbus/mock_session_manager_client.h
index afe8e37..14e879b 100644
--- a/chromeos/dbus/mock_session_manager_client.h
+++ b/chromeos/dbus/mock_session_manager_client.h
@@ -17,6 +17,7 @@ class MockSessionManagerClient : public SessionManagerClient {
   MockSessionManagerClient();
   virtual ~MockSessionManagerClient();
 
+  MOCK_METHOD1(Init, void(dbus::Bus* bus));
   MOCK_METHOD1(AddObserver, void(Observer*));
   MOCK_METHOD1(RemoveObserver, void(Observer*));
   MOCK_METHOD1(HasObserver, bool(Observer*));
diff --git a/chromeos/dbus/mock_shill_device_client.h b/chromeos/dbus/mock_shill_device_client.h
index eef766f..d473ed7 100644
--- a/chromeos/dbus/mock_shill_device_client.h
+++ b/chromeos/dbus/mock_shill_device_client.h
@@ -18,6 +18,7 @@ class MockShillDeviceClient : public ShillDeviceClient {
   MockShillDeviceClient();
   virtual ~MockShillDeviceClient();
 
+  MOCK_METHOD1(Init, void(dbus::Bus* bus));
   MOCK_METHOD2(AddPropertyChangedObserver,
                void(const dbus::ObjectPath& device_path,
                     ShillPropertyChangedObserver* observer));
diff --git a/chromeos/dbus/mock_shill_ipconfig_client.h b/chromeos/dbus/mock_shill_ipconfig_client.h
index 4a4bea3..4a35b37 100644
--- a/chromeos/dbus/mock_shill_ipconfig_client.h
+++ b/chromeos/dbus/mock_shill_ipconfig_client.h
@@ -18,6 +18,7 @@ class MockShillIPConfigClient : public ShillIPConfigClient {
   MockShillIPConfigClient();
   virtual ~MockShillIPConfigClient();
 
+  MOCK_METHOD1(Init, void(dbus::Bus* bus));
   MOCK_METHOD2(AddPropertyChangedObserver,
                void(const dbus::ObjectPath& ipconfig_path,
                     ShillPropertyChangedObserver* observer));
diff --git a/chromeos/dbus/mock_shill_manager_client.h b/chromeos/dbus/mock_shill_manager_client.h
index b62aebd..bf80b64 100644
--- a/chromeos/dbus/mock_shill_manager_client.h
+++ b/chromeos/dbus/mock_shill_manager_client.h
@@ -17,6 +17,7 @@ class MockShillManagerClient : public ShillManagerClient {
   MockShillManagerClient();
   virtual ~MockShillManagerClient();
 
+  MOCK_METHOD1(Init, void(dbus::Bus* bus));
   MOCK_METHOD1(AddPropertyChangedObserver,
                void(ShillPropertyChangedObserver* observer));
   MOCK_METHOD1(RemovePropertyChangedObserver,
diff --git a/chromeos/dbus/mock_shill_profile_client.h b/chromeos/dbus/mock_shill_profile_client.h
index b18a843..9bf2012 100644
--- a/chromeos/dbus/mock_shill_profile_client.h
+++ b/chromeos/dbus/mock_shill_profile_client.h
@@ -20,6 +20,7 @@ class MockShillProfileClient : public ShillProfileClient {
   MockShillProfileClient();
   virtual ~MockShillProfileClient();
 
+  MOCK_METHOD1(Init, void(dbus::Bus* bus));
   MOCK_METHOD2(AddPropertyChangedObserver,
                void(const dbus::ObjectPath& profile_path,
                     ShillPropertyChangedObserver* observer));
diff --git a/chromeos/dbus/mock_shill_service_client.h b/chromeos/dbus/mock_shill_service_client.h
index 6f4ab29..a890b51 100644
--- a/chromeos/dbus/mock_shill_service_client.h
+++ b/chromeos/dbus/mock_shill_service_client.h
@@ -18,6 +18,7 @@ class MockShillServiceClient : public ShillServiceClient {
   MockShillServiceClient();
   virtual ~MockShillServiceClient();
 
+  MOCK_METHOD1(Init, void(dbus::Bus* dbus));
   MOCK_METHOD2(AddPropertyChangedObserver,
                void(const dbus::ObjectPath& service_path,
                     ShillPropertyChangedObserver* observer));
diff --git a/chromeos/dbus/modem_messaging_client.cc b/chromeos/dbus/modem_messaging_client.cc
index 2aa12de..b421b7c 100644
--- a/chromeos/dbus/modem_messaging_client.cc
+++ b/chromeos/dbus/modem_messaging_client.cc
@@ -135,12 +135,11 @@ class ModemMessagingProxy {
 
 class CHROMEOS_EXPORT ModemMessagingClientImpl : public ModemMessagingClient {
  public:
-  explicit ModemMessagingClientImpl(dbus::Bus *bus)
-      : bus_(bus),
+  ModemMessagingClientImpl()
+      : bus_(NULL),
         proxies_deleter_(&proxies_) {
   }
 
-  // ModemMessagingClient override.
   virtual void SetSmsReceivedHandler(
       const std::string& service_name,
       const dbus::ObjectPath& object_path,
@@ -148,14 +147,12 @@ class CHROMEOS_EXPORT ModemMessagingClientImpl : public ModemMessagingClient {
     GetProxy(service_name, object_path)->SetSmsReceivedHandler(handler);
   }
 
-  // ModemMessagingClient override.
   virtual void ResetSmsReceivedHandler(
       const std::string& service_name,
       const dbus::ObjectPath& object_path) OVERRIDE {
     GetProxy(service_name, object_path)->ResetSmsReceivedHandler();
   }
 
-  // ModemMessagingClient override.
   virtual void Delete(const std::string& service_name,
                       const dbus::ObjectPath& object_path,
                       const dbus::ObjectPath& sms_path,
@@ -163,13 +160,17 @@ class CHROMEOS_EXPORT ModemMessagingClientImpl : public ModemMessagingClient {
     GetProxy(service_name, object_path)->Delete(sms_path, callback);
   }
 
-  // ModemMessagingClient override.
   virtual void List(const std::string& service_name,
                     const dbus::ObjectPath& object_path,
                     const ListCallback& callback) OVERRIDE {
     GetProxy(service_name, object_path)->List(callback);
   }
 
+ protected:
+  virtual void Init(dbus::Bus* bus) OVERRIDE {
+    bus_ = bus;
+  };
+
  private:
   typedef std::map<std::pair<std::string, std::string>, ModemMessagingProxy*>
       ProxyMap;
@@ -203,6 +204,7 @@ class CHROMEOS_EXPORT ModemMessagingClientStubImpl
   virtual ~ModemMessagingClientStubImpl() {}
 
   // ModemMessagingClient override.
+  virtual void Init(dbus::Bus* bus) OVERRIDE {}
   virtual void SetSmsReceivedHandler(
       const std::string& service_name,
       const dbus::ObjectPath& object_path,
@@ -268,10 +270,9 @@ ModemMessagingClient::~ModemMessagingClient() {}
 
 // static
 ModemMessagingClient* ModemMessagingClient::Create(
-    DBusClientImplementationType type,
-    dbus::Bus* bus) {
+    DBusClientImplementationType type) {
   if (type == REAL_DBUS_CLIENT_IMPLEMENTATION) {
-    return new ModemMessagingClientImpl(bus);
+    return new ModemMessagingClientImpl();
   }
   DCHECK_EQ(STUB_DBUS_CLIENT_IMPLEMENTATION, type);
   return new ModemMessagingClientStubImpl();
diff --git a/chromeos/dbus/modem_messaging_client.h b/chromeos/dbus/modem_messaging_client.h
index 8a5eb3d..d3ebc33 100644
--- a/chromeos/dbus/modem_messaging_client.h
+++ b/chromeos/dbus/modem_messaging_client.h
@@ -11,10 +11,10 @@
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "chromeos/chromeos_export.h"
+#include "chromeos/dbus/dbus_client.h"
 #include "chromeos/dbus/dbus_client_implementation_type.h"
 
 namespace dbus {
-class Bus;
 class ObjectPath;
 }
 
@@ -24,7 +24,7 @@ namespace chromeos {
 // org.freedesktop.ModemManager1.Modem.Messaging service.  All methods
 // should be called from the origin thread (UI thread) which
 // initializes the DBusThreadManager instance.
-class CHROMEOS_EXPORT ModemMessagingClient {
+class CHROMEOS_EXPORT ModemMessagingClient : public DBusClient {
  public:
   typedef base::Callback<void()> DeleteCallback;
   typedef base::Callback<void(const dbus::ObjectPath& message_path,
@@ -36,8 +36,7 @@ class CHROMEOS_EXPORT ModemMessagingClient {
 
   // Factory function, creates a new instance and returns ownership.
   // For normal usage, access the singleton via DBusThreadManager::Get().
-  static ModemMessagingClient* Create(DBusClientImplementationType type,
-                                      dbus::Bus* bus);
+  static ModemMessagingClient* Create(DBusClientImplementationType type);
 
   // Sets SmsReceived signal handler.
   virtual void SetSmsReceivedHandler(const std::string& service_name,
@@ -60,6 +59,8 @@ class CHROMEOS_EXPORT ModemMessagingClient {
                     const ListCallback& callback) = 0;
 
  protected:
+  friend class ModemMessagingClientTest;
+
   // Create() should be used instead.
   ModemMessagingClient();
 
diff --git a/chromeos/dbus/modem_messaging_client_unittest.cc b/chromeos/dbus/modem_messaging_client_unittest.cc
index f51e9f4..506ef9b 100644
--- a/chromeos/dbus/modem_messaging_client_unittest.cc
+++ b/chromeos/dbus/modem_messaging_client_unittest.cc
@@ -93,8 +93,9 @@ class ModemMessagingClientTest : public testing::Test {
     EXPECT_CALL(*mock_bus_.get(), ShutdownAndBlock()).WillOnce(Return());
 
     // Create a client with the mock bus.
-    client_.reset(ModemMessagingClient::Create(REAL_DBUS_CLIENT_IMPLEMENTATION,
-                                               mock_bus_.get()));
+    client_.reset(
+        ModemMessagingClient::Create(REAL_DBUS_CLIENT_IMPLEMENTATION));
+    client_->Init(mock_bus_.get());
   }
 
   virtual void TearDown() OVERRIDE {
diff --git a/chromeos/dbus/permission_broker_client.cc b/chromeos/dbus/permission_broker_client.cc
index cd86eba..4bf2699 100644
--- a/chromeos/dbus/permission_broker_client.cc
+++ b/chromeos/dbus/permission_broker_client.cc
@@ -22,10 +22,7 @@ namespace chromeos {
 
 class PermissionBrokerClientImpl : public PermissionBrokerClient {
  public:
-  explicit PermissionBrokerClientImpl(dbus::Bus* bus)
-      : proxy_(bus->GetObjectProxy(kPermissionBrokerServiceName,
-            dbus::ObjectPath(kPermissionBrokerServicePath))),
-        weak_ptr_factory_(this) {}
+  PermissionBrokerClientImpl() : proxy_(NULL), weak_ptr_factory_(this) {}
 
   virtual void RequestPathAccess(const std::string& path,
                                  const int interface_id,
@@ -56,6 +53,13 @@ class PermissionBrokerClientImpl : public PermissionBrokerClient {
                                   weak_ptr_factory_.GetWeakPtr(), callback));
   }
 
+ protected:
+  virtual void Init(dbus::Bus* bus) OVERRIDE {
+    proxy_ =
+        bus->GetObjectProxy(kPermissionBrokerServiceName,
+                            dbus::ObjectPath(kPermissionBrokerServicePath));
+  }
+
  private:
   // Handle a DBus response from the permission broker, invoking the callback
   // that the method was originally called with with the success response.
@@ -88,6 +92,7 @@ class PermissionBrokerClientStubImpl : public PermissionBrokerClient {
   PermissionBrokerClientStubImpl() {}
   virtual ~PermissionBrokerClientStubImpl() {}
 
+  virtual void Init(dbus::Bus* bus) OVERRIDE {}
   virtual void RequestPathAccess(const std::string& path,
                                  int interface_id,
                                  const ResultCallback& callback) OVERRIDE {
@@ -110,9 +115,9 @@ PermissionBrokerClient::PermissionBrokerClient() {}
 PermissionBrokerClient::~PermissionBrokerClient() {}
 
 PermissionBrokerClient* PermissionBrokerClient::Create(
-    DBusClientImplementationType type, dbus::Bus* bus) {
+    DBusClientImplementationType type) {
   if (type == REAL_DBUS_CLIENT_IMPLEMENTATION)
-    return new PermissionBrokerClientImpl(bus);
+    return new PermissionBrokerClientImpl();
   return new PermissionBrokerClientStubImpl();
 }
 
diff --git a/chromeos/dbus/permission_broker_client.h b/chromeos/dbus/permission_broker_client.h
index 645bcca..5780d8c 100644
--- a/chromeos/dbus/permission_broker_client.h
+++ b/chromeos/dbus/permission_broker_client.h
@@ -10,12 +10,9 @@
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "chromeos/chromeos_export.h"
+#include "chromeos/dbus/dbus_client.h"
 #include "chromeos/dbus/dbus_client_implementation_type.h"
 
-namespace dbus {
-class Bus;
-}  // namespace dbus
-
 namespace chromeos {
 
 // PermissionBrokerClient is used to communicate with the permission broker, a
@@ -25,7 +22,7 @@ namespace chromeos {
 // which the user the browser runs under normally wouldn't have access to. For
 // more details on the permission broker see:
 // http://git.chromium.org/gitweb/?p=chromiumos/platform/permission_broker.git
-class CHROMEOS_EXPORT PermissionBrokerClient {
+class CHROMEOS_EXPORT PermissionBrokerClient : public DBusClient {
  public:
   // The ResultCallback is used for both the RequestPathAccess and
   // RequestUsbAcess methods. Its boolean parameter represents the result of the
@@ -34,8 +31,7 @@ class CHROMEOS_EXPORT PermissionBrokerClient {
 
   virtual ~PermissionBrokerClient();
 
-  static PermissionBrokerClient* Create(DBusClientImplementationType type,
-                                        dbus::Bus* bus);
+  static PermissionBrokerClient* Create(DBusClientImplementationType type);
 
   // RequestPathAccess requests access to a single device node identified by
   // |path|. If |interface_id| value is passed (different than
diff --git a/chromeos/dbus/power_manager_client.cc b/chromeos/dbus/power_manager_client.cc
index 0669b44..548b053 100644
--- a/chromeos/dbus/power_manager_client.cc
+++ b/chromeos/dbus/power_manager_client.cc
@@ -41,7 +41,7 @@ const char kSuspendDelayDescription[] = "chrome";
 // The PowerManagerClient implementation used in production.
 class PowerManagerClientImpl : public PowerManagerClient {
  public:
-  explicit PowerManagerClientImpl(dbus::Bus* bus)
+  PowerManagerClientImpl()
       : origin_thread_id_(base::PlatformThread::CurrentId()),
         power_manager_proxy_(NULL),
         suspend_delay_id_(-1),
@@ -50,95 +50,7 @@ class PowerManagerClientImpl : public PowerManagerClient {
         suspend_is_pending_(false),
         num_pending_suspend_readiness_callbacks_(0),
         last_is_projecting_(false),
-        weak_ptr_factory_(this) {
-    power_manager_proxy_ = bus->GetObjectProxy(
-        power_manager::kPowerManagerServiceName,
-        dbus::ObjectPath(power_manager::kPowerManagerServicePath));
-
-    power_manager_proxy_->SetNameOwnerChangedCallback(
-        base::Bind(&PowerManagerClientImpl::NameOwnerChangedReceived,
-                   weak_ptr_factory_.GetWeakPtr()));
-
-    // Monitor the D-Bus signal for brightness changes. Only the power
-    // manager knows the actual brightness level. We don't cache the
-    // brightness level in Chrome as it'll make things less reliable.
-    power_manager_proxy_->ConnectToSignal(
-        power_manager::kPowerManagerInterface,
-        power_manager::kBrightnessChangedSignal,
-        base::Bind(&PowerManagerClientImpl::BrightnessChangedReceived,
-                   weak_ptr_factory_.GetWeakPtr()),
-        base::Bind(&PowerManagerClientImpl::SignalConnected,
-                   weak_ptr_factory_.GetWeakPtr()));
-
-    power_manager_proxy_->ConnectToSignal(
-        power_manager::kPowerManagerInterface,
-        power_manager::kPeripheralBatteryStatusSignal,
-        base::Bind(&PowerManagerClientImpl::PeripheralBatteryStatusReceived,
-                   weak_ptr_factory_.GetWeakPtr()),
-        base::Bind(&PowerManagerClientImpl::SignalConnected,
-                   weak_ptr_factory_.GetWeakPtr()));
-
-    power_manager_proxy_->ConnectToSignal(
-        power_manager::kPowerManagerInterface,
-        power_manager::kPowerSupplyPollSignal,
-        base::Bind(&PowerManagerClientImpl::PowerSupplyPollReceived,
-                   weak_ptr_factory_.GetWeakPtr()),
-        base::Bind(&PowerManagerClientImpl::SignalConnected,
-                   weak_ptr_factory_.GetWeakPtr()));
-
-    power_manager_proxy_->ConnectToSignal(
-        power_manager::kPowerManagerInterface,
-        power_manager::kIdleNotifySignal,
-        base::Bind(&PowerManagerClientImpl::IdleNotifySignalReceived,
-                   weak_ptr_factory_.GetWeakPtr()),
-        base::Bind(&PowerManagerClientImpl::SignalConnected,
-                   weak_ptr_factory_.GetWeakPtr()));
-
-    power_manager_proxy_->ConnectToSignal(
-        power_manager::kPowerManagerInterface,
-        power_manager::kInputEventSignal,
-        base::Bind(&PowerManagerClientImpl::InputEventReceived,
-                   weak_ptr_factory_.GetWeakPtr()),
-        base::Bind(&PowerManagerClientImpl::SignalConnected,
-                   weak_ptr_factory_.GetWeakPtr()));
-
-    power_manager_proxy_->ConnectToSignal(
-        power_manager::kPowerManagerInterface,
-        power_manager::kSuspendStateChangedSignal,
-        base::Bind(&PowerManagerClientImpl::SuspendStateChangedReceived,
-                   weak_ptr_factory_.GetWeakPtr()),
-        base::Bind(&PowerManagerClientImpl::SignalConnected,
-                   weak_ptr_factory_.GetWeakPtr()));
-
-    power_manager_proxy_->ConnectToSignal(
-        power_manager::kPowerManagerInterface,
-        power_manager::kSuspendImminentSignal,
-        base::Bind(
-            &PowerManagerClientImpl::SuspendImminentReceived,
-            weak_ptr_factory_.GetWeakPtr()),
-        base::Bind(&PowerManagerClientImpl::SignalConnected,
-                   weak_ptr_factory_.GetWeakPtr()));
-
-    power_manager_proxy_->ConnectToSignal(
-        power_manager::kPowerManagerInterface,
-        power_manager::kIdleActionImminentSignal,
-        base::Bind(
-            &PowerManagerClientImpl::IdleActionImminentReceived,
-            weak_ptr_factory_.GetWeakPtr()),
-        base::Bind(&PowerManagerClientImpl::SignalConnected,
-                   weak_ptr_factory_.GetWeakPtr()));
-
-    power_manager_proxy_->ConnectToSignal(
-        power_manager::kPowerManagerInterface,
-        power_manager::kIdleActionDeferredSignal,
-        base::Bind(
-            &PowerManagerClientImpl::IdleActionDeferredReceived,
-            weak_ptr_factory_.GetWeakPtr()),
-        base::Bind(&PowerManagerClientImpl::SignalConnected,
-                   weak_ptr_factory_.GetWeakPtr()));
-
-    RegisterSuspendDelay();
-  }
+        weak_ptr_factory_(this) {}
 
   virtual ~PowerManagerClientImpl() {
     // Here we should unregister suspend notifications from powerd,
@@ -311,6 +223,97 @@ class PowerManagerClientImpl : public PowerManagerClient {
                       weak_ptr_factory_.GetWeakPtr(), pending_suspend_id_);
   }
 
+ protected:
+  virtual void Init(dbus::Bus* bus) OVERRIDE {
+    power_manager_proxy_ = bus->GetObjectProxy(
+        power_manager::kPowerManagerServiceName,
+        dbus::ObjectPath(power_manager::kPowerManagerServicePath));
+
+    power_manager_proxy_->SetNameOwnerChangedCallback(
+        base::Bind(&PowerManagerClientImpl::NameOwnerChangedReceived,
+                   weak_ptr_factory_.GetWeakPtr()));
+
+    // Monitor the D-Bus signal for brightness changes. Only the power
+    // manager knows the actual brightness level. We don't cache the
+    // brightness level in Chrome as it'll make things less reliable.
+    power_manager_proxy_->ConnectToSignal(
+        power_manager::kPowerManagerInterface,
+        power_manager::kBrightnessChangedSignal,
+        base::Bind(&PowerManagerClientImpl::BrightnessChangedReceived,
+                   weak_ptr_factory_.GetWeakPtr()),
+        base::Bind(&PowerManagerClientImpl::SignalConnected,
+                   weak_ptr_factory_.GetWeakPtr()));
+
+    power_manager_proxy_->ConnectToSignal(
+        power_manager::kPowerManagerInterface,
+        power_manager::kPeripheralBatteryStatusSignal,
+        base::Bind(&PowerManagerClientImpl::PeripheralBatteryStatusReceived,
+                   weak_ptr_factory_.GetWeakPtr()),
+        base::Bind(&PowerManagerClientImpl::SignalConnected,
+                   weak_ptr_factory_.GetWeakPtr()));
+
+    power_manager_proxy_->ConnectToSignal(
+        power_manager::kPowerManagerInterface,
+        power_manager::kPowerSupplyPollSignal,
+        base::Bind(&PowerManagerClientImpl::PowerSupplyPollReceived,
+                   weak_ptr_factory_.GetWeakPtr()),
+        base::Bind(&PowerManagerClientImpl::SignalConnected,
+                   weak_ptr_factory_.GetWeakPtr()));
+
+    power_manager_proxy_->ConnectToSignal(
+        power_manager::kPowerManagerInterface,
+        power_manager::kIdleNotifySignal,
+        base::Bind(&PowerManagerClientImpl::IdleNotifySignalReceived,
+                   weak_ptr_factory_.GetWeakPtr()),
+        base::Bind(&PowerManagerClientImpl::SignalConnected,
+                   weak_ptr_factory_.GetWeakPtr()));
+
+    power_manager_proxy_->ConnectToSignal(
+        power_manager::kPowerManagerInterface,
+        power_manager::kInputEventSignal,
+        base::Bind(&PowerManagerClientImpl::InputEventReceived,
+                   weak_ptr_factory_.GetWeakPtr()),
+        base::Bind(&PowerManagerClientImpl::SignalConnected,
+                   weak_ptr_factory_.GetWeakPtr()));
+
+    power_manager_proxy_->ConnectToSignal(
+        power_manager::kPowerManagerInterface,
+        power_manager::kSuspendStateChangedSignal,
+        base::Bind(&PowerManagerClientImpl::SuspendStateChangedReceived,
+                   weak_ptr_factory_.GetWeakPtr()),
+        base::Bind(&PowerManagerClientImpl::SignalConnected,
+                   weak_ptr_factory_.GetWeakPtr()));
+
+    power_manager_proxy_->ConnectToSignal(
+        power_manager::kPowerManagerInterface,
+        power_manager::kSuspendImminentSignal,
+        base::Bind(
+            &PowerManagerClientImpl::SuspendImminentReceived,
+            weak_ptr_factory_.GetWeakPtr()),
+        base::Bind(&PowerManagerClientImpl::SignalConnected,
+                   weak_ptr_factory_.GetWeakPtr()));
+
+    power_manager_proxy_->ConnectToSignal(
+        power_manager::kPowerManagerInterface,
+        power_manager::kIdleActionImminentSignal,
+        base::Bind(
+            &PowerManagerClientImpl::IdleActionImminentReceived,
+            weak_ptr_factory_.GetWeakPtr()),
+        base::Bind(&PowerManagerClientImpl::SignalConnected,
+                   weak_ptr_factory_.GetWeakPtr()));
+
+    power_manager_proxy_->ConnectToSignal(
+        power_manager::kPowerManagerInterface,
+        power_manager::kIdleActionDeferredSignal,
+        base::Bind(
+            &PowerManagerClientImpl::IdleActionDeferredReceived,
+            weak_ptr_factory_.GetWeakPtr()),
+        base::Bind(&PowerManagerClientImpl::SignalConnected,
+                   weak_ptr_factory_.GetWeakPtr()));
+
+    RegisterSuspendDelay();
+  }
+
  private:
   // Returns true if the current thread is the origin thread.
   bool OnOriginThread() {
@@ -671,7 +674,12 @@ class PowerManagerClientStubImpl : public PowerManagerClient {
         brightness_(50.0),
         pause_count_(2),
         cycle_count_(0),
-        weak_ptr_factory_(this) {
+        weak_ptr_factory_(this) {}
+
+  virtual ~PowerManagerClientStubImpl() {}
+
+  // PowerManagerClient overrides
+  virtual void Init(dbus::Bus* bus) OVERRIDE {
     if (CommandLine::ForCurrentProcess()->HasSwitch(
         chromeos::switches::kEnableStubInteractive)) {
       const int kStatusUpdateMs = 1000;
@@ -681,10 +689,6 @@ class PowerManagerClientStubImpl : public PowerManagerClient {
     }
   }
 
-  virtual ~PowerManagerClientStubImpl() {}
-
-  // PowerManagerClient overrides:
-
   virtual void AddObserver(Observer* observer) OVERRIDE {
     observers_.AddObserver(observer);
   }
@@ -856,10 +860,9 @@ PowerManagerClient::~PowerManagerClient() {
 
 // static
 PowerManagerClient* PowerManagerClient::Create(
-    DBusClientImplementationType type,
-    dbus::Bus* bus) {
+    DBusClientImplementationType type) {
   if (type == REAL_DBUS_CLIENT_IMPLEMENTATION)
-    return new PowerManagerClientImpl(bus);
+    return new PowerManagerClientImpl();
   DCHECK_EQ(STUB_DBUS_CLIENT_IMPLEMENTATION, type);
   return new PowerManagerClientStubImpl();
 }
diff --git a/chromeos/dbus/power_manager_client.h b/chromeos/dbus/power_manager_client.h
index 5ddd711..e728f10 100644
--- a/chromeos/dbus/power_manager_client.h
+++ b/chromeos/dbus/power_manager_client.h
@@ -11,13 +11,10 @@
 #include "base/callback.h"
 #include "base/time/time.h"
 #include "chromeos/chromeos_export.h"
+#include "chromeos/dbus/dbus_client.h"
 #include "chromeos/dbus/dbus_client_implementation_type.h"
 #include "third_party/cros_system_api/dbus/service_constants.h"
 
-namespace dbus {
-class Bus;
-}
-
 namespace power_manager {
 class PowerManagementPolicy;
 class PowerSupplyProperties;
@@ -32,7 +29,7 @@ typedef base::Callback<void(void)> IdleNotificationCallback;
 typedef base::Callback<void(double)> GetScreenBrightnessPercentCallback;
 
 // PowerManagerClient is used to communicate with the power manager.
-class CHROMEOS_EXPORT PowerManagerClient {
+class CHROMEOS_EXPORT PowerManagerClient : public DBusClient {
  public:
   // Interface for observing changes from the power manager.
   class Observer {
@@ -161,8 +158,7 @@ class CHROMEOS_EXPORT PowerManagerClient {
   virtual base::Closure GetSuspendReadinessCallback() = 0;
 
   // Creates the instance.
-  static PowerManagerClient* Create(DBusClientImplementationType type,
-                                    dbus::Bus* bus);
+  static PowerManagerClient* Create(DBusClientImplementationType type);
 
   virtual ~PowerManagerClient();
 
diff --git a/chromeos/dbus/session_manager_client.cc b/chromeos/dbus/session_manager_client.cc
index e842f88..f75a9d4 100644
--- a/chromeos/dbus/session_manager_client.cc
+++ b/chromeos/dbus/session_manager_client.cc
@@ -28,66 +28,9 @@ namespace chromeos {
 // The SessionManagerClient implementation used in production.
 class SessionManagerClientImpl : public SessionManagerClient {
  public:
-  explicit SessionManagerClientImpl(dbus::Bus* bus)
-      : session_manager_proxy_(bus->GetObjectProxy(
-            login_manager::kSessionManagerServiceName,
-            dbus::ObjectPath(login_manager::kSessionManagerServicePath))),
-        blocking_method_caller_(bus, session_manager_proxy_),
-        weak_ptr_factory_(this) {
-    // Signals emitted on Chromium's interface.  Many of these ought to be
-    // method calls instead.
-    session_manager_proxy_->ConnectToSignal(
-        chromium::kChromiumInterface,
-        chromium::kOwnerKeySetSignal,
-        base::Bind(&SessionManagerClientImpl::OwnerKeySetReceived,
-                   weak_ptr_factory_.GetWeakPtr()),
-        base::Bind(&SessionManagerClientImpl::SignalConnected,
-                   weak_ptr_factory_.GetWeakPtr()));
-    session_manager_proxy_->ConnectToSignal(
-        chromium::kChromiumInterface,
-        chromium::kPropertyChangeCompleteSignal,
-        base::Bind(&SessionManagerClientImpl::PropertyChangeCompleteReceived,
-                   weak_ptr_factory_.GetWeakPtr()),
-        base::Bind(&SessionManagerClientImpl::SignalConnected,
-                   weak_ptr_factory_.GetWeakPtr()));
-    session_manager_proxy_->ConnectToSignal(
-        chromium::kChromiumInterface,
-        chromium::kLockScreenSignal,
-        base::Bind(&SessionManagerClientImpl::ScreenLockReceived,
-                   weak_ptr_factory_.GetWeakPtr()),
-        base::Bind(&SessionManagerClientImpl::SignalConnected,
-                   weak_ptr_factory_.GetWeakPtr()));
-    session_manager_proxy_->ConnectToSignal(
-        chromium::kChromiumInterface,
-        chromium::kUnlockScreenSignal,
-        base::Bind(&SessionManagerClientImpl::ScreenUnlockReceived,
-                   weak_ptr_factory_.GetWeakPtr()),
-        base::Bind(&SessionManagerClientImpl::SignalConnected,
-                   weak_ptr_factory_.GetWeakPtr()));
-    session_manager_proxy_->ConnectToSignal(
-        chromium::kChromiumInterface,
-        chromium::kLivenessRequestedSignal,
-        base::Bind(&SessionManagerClientImpl::LivenessRequestedReceived,
-                   weak_ptr_factory_.GetWeakPtr()),
-        base::Bind(&SessionManagerClientImpl::SignalConnected,
-                   weak_ptr_factory_.GetWeakPtr()));
-
-    // Signals emitted on the session manager's interface.
-    session_manager_proxy_->ConnectToSignal(
-        login_manager::kSessionManagerInterface,
-        login_manager::kScreenIsLockedSignal,
-        base::Bind(&SessionManagerClientImpl::ScreenIsLockedReceived,
-                   weak_ptr_factory_.GetWeakPtr()),
-        base::Bind(&SessionManagerClientImpl::SignalConnected,
-                   weak_ptr_factory_.GetWeakPtr()));
-    session_manager_proxy_->ConnectToSignal(
-        login_manager::kSessionManagerInterface,
-        login_manager::kScreenIsUnlockedSignal,
-        base::Bind(&SessionManagerClientImpl::ScreenIsUnlockedReceived,
-                   weak_ptr_factory_.GetWeakPtr()),
-        base::Bind(&SessionManagerClientImpl::SignalConnected,
-                   weak_ptr_factory_.GetWeakPtr()));
-  }
+  SessionManagerClientImpl()
+      : session_manager_proxy_(NULL),
+        weak_ptr_factory_(this) {}
 
   virtual ~SessionManagerClientImpl() {
   }
@@ -231,7 +174,7 @@ class SessionManagerClientImpl : public SessionManagerClient {
     dbus::MessageWriter writer(&method_call);
     writer.AppendString(username);
     scoped_ptr<dbus::Response> response =
-        blocking_method_caller_.CallMethodAndBlock(&method_call);
+        blocking_method_caller_->CallMethodAndBlock(&method_call);
     std::string policy;
     ExtractString(login_manager::kSessionManagerRetrievePolicyForUser,
                   response.get(),
@@ -300,6 +243,69 @@ class SessionManagerClientImpl : public SessionManagerClient {
         dbus::ObjectProxy::EmptyResponseCallback());
   }
 
+ protected:
+  virtual void Init(dbus::Bus* bus) OVERRIDE {
+    session_manager_proxy_ = bus->GetObjectProxy(
+        login_manager::kSessionManagerServiceName,
+        dbus::ObjectPath(login_manager::kSessionManagerServicePath));
+    blocking_method_caller_.reset(
+        new BlockingMethodCaller(bus, session_manager_proxy_));
+
+    // Signals emitted on Chromium's interface.  Many of these ought to be
+    // method calls instead.
+    session_manager_proxy_->ConnectToSignal(
+        chromium::kChromiumInterface,
+        chromium::kOwnerKeySetSignal,
+        base::Bind(&SessionManagerClientImpl::OwnerKeySetReceived,
+                   weak_ptr_factory_.GetWeakPtr()),
+        base::Bind(&SessionManagerClientImpl::SignalConnected,
+                   weak_ptr_factory_.GetWeakPtr()));
+    session_manager_proxy_->ConnectToSignal(
+        chromium::kChromiumInterface,
+        chromium::kPropertyChangeCompleteSignal,
+        base::Bind(&SessionManagerClientImpl::PropertyChangeCompleteReceived,
+                   weak_ptr_factory_.GetWeakPtr()),
+        base::Bind(&SessionManagerClientImpl::SignalConnected,
+                   weak_ptr_factory_.GetWeakPtr()));
+    session_manager_proxy_->ConnectToSignal(
+        chromium::kChromiumInterface,
+        chromium::kLockScreenSignal,
+        base::Bind(&SessionManagerClientImpl::ScreenLockReceived,
+                   weak_ptr_factory_.GetWeakPtr()),
+        base::Bind(&SessionManagerClientImpl::SignalConnected,
+                   weak_ptr_factory_.GetWeakPtr()));
+    session_manager_proxy_->ConnectToSignal(
+        chromium::kChromiumInterface,
+        chromium::kUnlockScreenSignal,
+        base::Bind(&SessionManagerClientImpl::ScreenUnlockReceived,
+                   weak_ptr_factory_.GetWeakPtr()),
+        base::Bind(&SessionManagerClientImpl::SignalConnected,
+                   weak_ptr_factory_.GetWeakPtr()));
+    session_manager_proxy_->ConnectToSignal(
+        chromium::kChromiumInterface,
+        chromium::kLivenessRequestedSignal,
+        base::Bind(&SessionManagerClientImpl::LivenessRequestedReceived,
+                   weak_ptr_factory_.GetWeakPtr()),
+        base::Bind(&SessionManagerClientImpl::SignalConnected,
+                   weak_ptr_factory_.GetWeakPtr()));
+
+    // Signals emitted on the session manager's interface.
+    session_manager_proxy_->ConnectToSignal(
+        login_manager::kSessionManagerInterface,
+        login_manager::kScreenIsLockedSignal,
+        base::Bind(&SessionManagerClientImpl::ScreenIsLockedReceived,
+                   weak_ptr_factory_.GetWeakPtr()),
+        base::Bind(&SessionManagerClientImpl::SignalConnected,
+                   weak_ptr_factory_.GetWeakPtr()));
+    session_manager_proxy_->ConnectToSignal(
+        login_manager::kSessionManagerInterface,
+        login_manager::kScreenIsUnlockedSignal,
+        base::Bind(&SessionManagerClientImpl::ScreenIsUnlockedReceived,
+                   weak_ptr_factory_.GetWeakPtr()),
+        base::Bind(&SessionManagerClientImpl::SignalConnected,
+                   weak_ptr_factory_.GetWeakPtr()));
+  }
+
  private:
   // Makes a method call to the session manager with no arguments and no
   // response.
@@ -513,7 +519,7 @@ class SessionManagerClientImpl : public SessionManagerClient {
   }
 
   dbus::ObjectProxy* session_manager_proxy_;
-  BlockingMethodCaller blocking_method_caller_;
+  scoped_ptr<BlockingMethodCaller> blocking_method_caller_;
   ObserverList<Observer> observers_;
 
   // Note: This should remain the last member so it'll be destroyed and
@@ -527,7 +533,11 @@ class SessionManagerClientImpl : public SessionManagerClient {
 // which does nothing.
 class SessionManagerClientStubImpl : public SessionManagerClient {
  public:
-  SessionManagerClientStubImpl() {
+  SessionManagerClientStubImpl() {}
+  virtual ~SessionManagerClientStubImpl() {}
+
+  // SessionManagerClient overrides
+  virtual void Init(dbus::Bus* bus) OVERRIDE {
     // Make sure that there are no keys left over from a previous browser run.
     base::FilePath user_policy_key_dir;
     if (PathService::Get(chromeos::DIR_USER_POLICY_KEYS,
@@ -539,9 +549,7 @@ class SessionManagerClientStubImpl : public SessionManagerClient {
           false);
     }
   }
-  virtual ~SessionManagerClientStubImpl() {}
 
-  // SessionManagerClient overrides.
   virtual void AddObserver(Observer* observer) OVERRIDE {
     observers_.AddObserver(observer);
   }
@@ -664,10 +672,9 @@ SessionManagerClient::~SessionManagerClient() {
 }
 
 SessionManagerClient* SessionManagerClient::Create(
-    DBusClientImplementationType type,
-    dbus::Bus* bus) {
+    DBusClientImplementationType type) {
   if (type == REAL_DBUS_CLIENT_IMPLEMENTATION)
-    return new SessionManagerClientImpl(bus);
+    return new SessionManagerClientImpl();
   DCHECK_EQ(STUB_DBUS_CLIENT_IMPLEMENTATION, type);
   return new SessionManagerClientStubImpl();
 }
diff --git a/chromeos/dbus/session_manager_client.h b/chromeos/dbus/session_manager_client.h
index 45b9b14..f09a041 100644
--- a/chromeos/dbus/session_manager_client.h
+++ b/chromeos/dbus/session_manager_client.h
@@ -11,16 +11,13 @@
 #include "base/callback.h"
 #include "base/observer_list.h"
 #include "chromeos/chromeos_export.h"
+#include "chromeos/dbus/dbus_client.h"
 #include "chromeos/dbus/dbus_client_implementation_type.h"
 
-namespace dbus {
-class Bus;
-}  // namespace dbus
-
 namespace chromeos {
 
 // SessionManagerClient is used to communicate with the session manager.
-class CHROMEOS_EXPORT SessionManagerClient {
+class CHROMEOS_EXPORT SessionManagerClient : public DBusClient {
  public:
   // Interface for observing changes from the session manager.
   class Observer {
@@ -173,8 +170,7 @@ class CHROMEOS_EXPORT SessionManagerClient {
                                const std::vector<std::string>& flags) = 0;
 
   // Creates the instance.
-  static SessionManagerClient* Create(DBusClientImplementationType type,
-                                      dbus::Bus* bus);
+  static SessionManagerClient* Create(DBusClientImplementationType type);
 
   virtual ~SessionManagerClient();
 
diff --git a/chromeos/dbus/shill_device_client.cc b/chromeos/dbus/shill_device_client.cc
index ccab2b9..420f586 100644
--- a/chromeos/dbus/shill_device_client.cc
+++ b/chromeos/dbus/shill_device_client.cc
@@ -24,8 +24,8 @@ namespace {
 // The ShillDeviceClient implementation.
 class ShillDeviceClientImpl : public ShillDeviceClient {
  public:
-  explicit ShillDeviceClientImpl(dbus::Bus* bus)
-      : bus_(bus) {
+  explicit ShillDeviceClientImpl()
+      : bus_(NULL) {
   }
 
   virtual ~ShillDeviceClientImpl() {
@@ -196,6 +196,11 @@ class ShillDeviceClientImpl : public ShillDeviceClient {
     return NULL;
   }
 
+ protected:
+  virtual void Init(dbus::Bus* bus) OVERRIDE {
+    bus_ = bus;
+  }
+
  private:
   typedef std::map<std::string, ShillClientHelper*> HelperMap;
 
@@ -231,10 +236,9 @@ ShillDeviceClient::~ShillDeviceClient() {}
 
 // static
 ShillDeviceClient* ShillDeviceClient::Create(
-    DBusClientImplementationType type,
-    dbus::Bus* bus) {
+    DBusClientImplementationType type) {
   if (type == REAL_DBUS_CLIENT_IMPLEMENTATION)
-    return new ShillDeviceClientImpl(bus);
+    return new ShillDeviceClientImpl();
   DCHECK_EQ(STUB_DBUS_CLIENT_IMPLEMENTATION, type);
   return new ShillDeviceClientStub();
 }
diff --git a/chromeos/dbus/shill_device_client.h b/chromeos/dbus/shill_device_client.h
index 2047059..4600e37 100644
--- a/chromeos/dbus/shill_device_client.h
+++ b/chromeos/dbus/shill_device_client.h
@@ -10,6 +10,7 @@
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "chromeos/chromeos_export.h"
+#include "chromeos/dbus/dbus_client.h"
 #include "chromeos/dbus/dbus_client_implementation_type.h"
 #include "chromeos/dbus/shill_client_helper.h"
 
@@ -22,7 +23,6 @@ class DictionaryValue;
 
 namespace dbus {
 
-class Bus;
 class ObjectPath;
 
 }  // namespace dbus
@@ -34,7 +34,7 @@ class ShillPropertyChangedObserver;
 // ShillDeviceClient is used to communicate with the Shill Device service.
 // All methods should be called from the origin thread which initializes the
 // DBusThreadManager instance.
-class CHROMEOS_EXPORT ShillDeviceClient {
+class CHROMEOS_EXPORT ShillDeviceClient : public DBusClient {
  public:
   typedef ShillClientHelper::PropertyChangedHandler PropertyChangedHandler;
   typedef ShillClientHelper::DictionaryValueCallback DictionaryValueCallback;
@@ -62,8 +62,7 @@ class CHROMEOS_EXPORT ShillDeviceClient {
 
   // Factory function, creates a new instance which is owned by the caller.
   // For normal usage, access the singleton via DBusThreadManager::Get().
-  static ShillDeviceClient* Create(DBusClientImplementationType type,
-                                      dbus::Bus* bus);
+  static ShillDeviceClient* Create(DBusClientImplementationType type);
 
   // Adds a property changed |observer| for the device at |device_path|.
   virtual void AddPropertyChangedObserver(
@@ -160,6 +159,8 @@ class CHROMEOS_EXPORT ShillDeviceClient {
   virtual TestInterface* GetTestInterface() = 0;
 
  protected:
+  friend class ShillDeviceClientTest;
+
   // Create() should be used instead.
   ShillDeviceClient();
 
diff --git a/chromeos/dbus/shill_device_client_stub.cc b/chromeos/dbus/shill_device_client_stub.cc
index f7f39da..a32febd 100644
--- a/chromeos/dbus/shill_device_client_stub.cc
+++ b/chromeos/dbus/shill_device_client_stub.cc
@@ -30,7 +30,6 @@ void ErrorFunction(const std::string& error_name,
 }  // namespace
 
 ShillDeviceClientStub::ShillDeviceClientStub() : weak_ptr_factory_(this) {
-  SetDefaultProperties();
 }
 
 ShillDeviceClientStub::~ShillDeviceClientStub() {
@@ -40,6 +39,10 @@ ShillDeviceClientStub::~ShillDeviceClientStub() {
 
 // ShillDeviceClient overrides.
 
+void ShillDeviceClientStub::Init(dbus::Bus* bus) {
+  SetDefaultProperties();
+}
+
 void ShillDeviceClientStub::AddPropertyChangedObserver(
     const dbus::ObjectPath& device_path,
     ShillPropertyChangedObserver* observer){
diff --git a/chromeos/dbus/shill_device_client_stub.h b/chromeos/dbus/shill_device_client_stub.h
index 8038cc7..fe2ca8c 100644
--- a/chromeos/dbus/shill_device_client_stub.h
+++ b/chromeos/dbus/shill_device_client_stub.h
@@ -20,7 +20,8 @@ class ShillDeviceClientStub : public ShillDeviceClient,
   ShillDeviceClientStub();
   virtual ~ShillDeviceClientStub();
 
-  // ShillDeviceClient overrides.
+  // ShillDeviceClient overrides
+  virtual void Init(dbus::Bus* bus) OVERRIDE;
   virtual void AddPropertyChangedObserver(
       const dbus::ObjectPath& device_path,
       ShillPropertyChangedObserver* observer) OVERRIDE;
diff --git a/chromeos/dbus/shill_device_client_unittest.cc b/chromeos/dbus/shill_device_client_unittest.cc
index 4149b17..52e50a9 100644
--- a/chromeos/dbus/shill_device_client_unittest.cc
+++ b/chromeos/dbus/shill_device_client_unittest.cc
@@ -59,8 +59,8 @@ class ShillDeviceClientTest : public ShillClientUnittestBase {
   virtual void SetUp() {
     ShillClientUnittestBase::SetUp();
     // Create a client with the mock bus.
-    client_.reset(ShillDeviceClient::Create(REAL_DBUS_CLIENT_IMPLEMENTATION,
-                                            mock_bus_.get()));
+    client_.reset(ShillDeviceClient::Create(REAL_DBUS_CLIENT_IMPLEMENTATION));
+    client_->Init(mock_bus_.get());
     // Run the message loop to run the signal connection result callback.
     message_loop_.RunUntilIdle();
   }
diff --git a/chromeos/dbus/shill_ipconfig_client.cc b/chromeos/dbus/shill_ipconfig_client.cc
index 2171590..6c6c750 100644
--- a/chromeos/dbus/shill_ipconfig_client.cc
+++ b/chromeos/dbus/shill_ipconfig_client.cc
@@ -24,7 +24,7 @@ namespace {
 // The ShillIPConfigClient implementation.
 class ShillIPConfigClientImpl : public ShillIPConfigClient {
  public:
-  explicit ShillIPConfigClientImpl(dbus::Bus* bus);
+  ShillIPConfigClientImpl();
 
   ////////////////////////////////////
   // ShillIPConfigClient overrides.
@@ -55,6 +55,11 @@ class ShillIPConfigClientImpl : public ShillIPConfigClient {
   virtual void Remove(const dbus::ObjectPath& ipconfig_path,
                       const VoidDBusMethodCallback& callback) OVERRIDE;
 
+ protected:
+  virtual void Init(dbus::Bus* bus) OVERRIDE {
+    bus_ = bus;
+  }
+
  private:
   typedef std::map<std::string, ShillClientHelper*> HelperMap;
 
@@ -80,8 +85,8 @@ class ShillIPConfigClientImpl : public ShillIPConfigClient {
   DISALLOW_COPY_AND_ASSIGN(ShillIPConfigClientImpl);
 };
 
-ShillIPConfigClientImpl::ShillIPConfigClientImpl(dbus::Bus* bus)
-    : bus_(bus),
+ShillIPConfigClientImpl::ShillIPConfigClientImpl()
+    : bus_(NULL),
       helpers_deleter_(&helpers_) {
 }
 
@@ -178,10 +183,9 @@ ShillIPConfigClient::~ShillIPConfigClient() {}
 
 // static
 ShillIPConfigClient* ShillIPConfigClient::Create(
-    DBusClientImplementationType type,
-    dbus::Bus* bus) {
+    DBusClientImplementationType type) {
   if (type == REAL_DBUS_CLIENT_IMPLEMENTATION)
-    return new ShillIPConfigClientImpl(bus);
+    return new ShillIPConfigClientImpl();
   DCHECK_EQ(STUB_DBUS_CLIENT_IMPLEMENTATION, type);
   return new ShillIPConfigClientStub();
 }
diff --git a/chromeos/dbus/shill_ipconfig_client.h b/chromeos/dbus/shill_ipconfig_client.h
index b311c56..df6db23 100644
--- a/chromeos/dbus/shill_ipconfig_client.h
+++ b/chromeos/dbus/shill_ipconfig_client.h
@@ -10,6 +10,7 @@
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "chromeos/chromeos_export.h"
+#include "chromeos/dbus/dbus_client.h"
 #include "chromeos/dbus/dbus_client_implementation_type.h"
 #include "chromeos/dbus/shill_client_helper.h"
 
@@ -22,7 +23,6 @@ class DictionaryValue;
 
 namespace dbus {
 
-class Bus;
 class ObjectPath;
 
 }  // namespace dbus
@@ -34,7 +34,7 @@ class ShillPropertyChangedObserver;
 // ShillIPConfigClient is used to communicate with the Shill IPConfig
 // service.  All methods should be called from the origin thread which
 // initializes the DBusThreadManager instance.
-class CHROMEOS_EXPORT ShillIPConfigClient {
+class CHROMEOS_EXPORT ShillIPConfigClient : public DBusClient {
  public:
   typedef ShillClientHelper::PropertyChangedHandler PropertyChangedHandler;
   typedef ShillClientHelper::DictionaryValueCallback DictionaryValueCallback;
@@ -42,8 +42,7 @@ class CHROMEOS_EXPORT ShillIPConfigClient {
 
   // Factory function, creates a new instance which is owned by the caller.
   // For normal usage, access the singleton via DBusThreadManager::Get().
-  static ShillIPConfigClient* Create(DBusClientImplementationType type,
-                                        dbus::Bus* bus);
+  static ShillIPConfigClient* Create(DBusClientImplementationType type);
 
   // Adds a property changed |observer| for the ipconfig at |ipconfig_path|.
   virtual void AddPropertyChangedObserver(
@@ -93,6 +92,8 @@ class CHROMEOS_EXPORT ShillIPConfigClient {
                       const VoidDBusMethodCallback& callback) = 0;
 
  protected:
+  friend class ShillIPConfigClientTest;
+
   // Create() should be used instead.
   ShillIPConfigClient();
 
diff --git a/chromeos/dbus/shill_ipconfig_client_stub.cc b/chromeos/dbus/shill_ipconfig_client_stub.cc
index ccccfd4..a29d479 100644
--- a/chromeos/dbus/shill_ipconfig_client_stub.cc
+++ b/chromeos/dbus/shill_ipconfig_client_stub.cc
@@ -24,6 +24,9 @@ ShillIPConfigClientStub::ShillIPConfigClientStub() : weak_ptr_factory_(this) {
 ShillIPConfigClientStub::~ShillIPConfigClientStub() {
 }
 
+void ShillIPConfigClientStub::Init(dbus::Bus* bus) {
+}
+
 void ShillIPConfigClientStub::AddPropertyChangedObserver(
     const dbus::ObjectPath& ipconfig_path,
     ShillPropertyChangedObserver* observer) {
diff --git a/chromeos/dbus/shill_ipconfig_client_stub.h b/chromeos/dbus/shill_ipconfig_client_stub.h
index bc77486..1122d77 100644
--- a/chromeos/dbus/shill_ipconfig_client_stub.h
+++ b/chromeos/dbus/shill_ipconfig_client_stub.h
@@ -18,7 +18,8 @@ class ShillIPConfigClientStub : public ShillIPConfigClient {
   ShillIPConfigClientStub();
   virtual ~ShillIPConfigClientStub();
 
-  // ShillIPConfigClient overrides:
+  // ShillIPConfigClient overrides
+  virtual void Init(dbus::Bus* bus) OVERRIDE;
   virtual void AddPropertyChangedObserver(
       const dbus::ObjectPath& ipconfig_path,
       ShillPropertyChangedObserver* observer) OVERRIDE;
diff --git a/chromeos/dbus/shill_ipconfig_client_unittest.cc b/chromeos/dbus/shill_ipconfig_client_unittest.cc
index 424935f..8ea537e 100644
--- a/chromeos/dbus/shill_ipconfig_client_unittest.cc
+++ b/chromeos/dbus/shill_ipconfig_client_unittest.cc
@@ -33,8 +33,8 @@ class ShillIPConfigClientTest : public ShillClientUnittestBase {
   virtual void SetUp() {
     ShillClientUnittestBase::SetUp();
     // Create a client with the mock bus.
-    client_.reset(ShillIPConfigClient::Create(REAL_DBUS_CLIENT_IMPLEMENTATION,
-                                              mock_bus_.get()));
+    client_.reset(ShillIPConfigClient::Create(REAL_DBUS_CLIENT_IMPLEMENTATION));
+    client_->Init(mock_bus_.get());
     // Run the message loop to run the signal connection result callback.
     message_loop_.RunUntilIdle();
   }
diff --git a/chromeos/dbus/shill_manager_client.cc b/chromeos/dbus/shill_manager_client.cc
index fca8ba0..70f2095 100644
--- a/chromeos/dbus/shill_manager_client.cc
+++ b/chromeos/dbus/shill_manager_client.cc
@@ -24,37 +24,31 @@ namespace {
 // The ShillManagerClient implementation.
 class ShillManagerClientImpl : public ShillManagerClient {
  public:
-  explicit ShillManagerClientImpl(dbus::Bus* bus)
-      : proxy_(bus->GetObjectProxy(
-          flimflam::kFlimflamServiceName,
-          dbus::ObjectPath(flimflam::kFlimflamServicePath))),
-        helper_(bus, proxy_) {
-    helper_.MonitorPropertyChanged(flimflam::kFlimflamManagerInterface);
-  }
+  ShillManagerClientImpl() : proxy_(NULL) {}
 
   ////////////////////////////////////
   // ShillManagerClient overrides.
   virtual void AddPropertyChangedObserver(
       ShillPropertyChangedObserver* observer) OVERRIDE {
-    helper_.AddPropertyChangedObserver(observer);
+    helper_->AddPropertyChangedObserver(observer);
   }
 
   virtual void RemovePropertyChangedObserver(
       ShillPropertyChangedObserver* observer) OVERRIDE {
-    helper_.RemovePropertyChangedObserver(observer);
+    helper_->RemovePropertyChangedObserver(observer);
   }
 
   virtual void GetProperties(const DictionaryValueCallback& callback) OVERRIDE {
     dbus::MethodCall method_call(flimflam::kFlimflamManagerInterface,
                                  flimflam::kGetPropertiesFunction);
-    helper_.CallDictionaryValueMethod(&method_call, callback);
+    helper_->CallDictionaryValueMethod(&method_call, callback);
   }
 
   virtual void GetNetworksForGeolocation(
       const DictionaryValueCallback& callback) OVERRIDE {
     dbus::MethodCall method_call(flimflam::kFlimflamManagerInterface,
                                  shill::kGetNetworksForGeolocation);
-    helper_.CallDictionaryValueMethod(&method_call, callback);
+    helper_->CallDictionaryValueMethod(&method_call, callback);
   }
 
   virtual void SetProperty(const std::string& name,
@@ -66,7 +60,7 @@ class ShillManagerClientImpl : public ShillManagerClient {
     dbus::MessageWriter writer(&method_call);
     writer.AppendString(name);
     ShillClientHelper::AppendValueDataAsVariant(&writer, value);
-    helper_.CallVoidMethodWithErrorCallback(&method_call,
+    helper_->CallVoidMethodWithErrorCallback(&method_call,
                                             callback,
                                             error_callback);
   }
@@ -78,7 +72,7 @@ class ShillManagerClientImpl : public ShillManagerClient {
                                  flimflam::kRequestScanFunction);
     dbus::MessageWriter writer(&method_call);
     writer.AppendString(type);
-    helper_.CallVoidMethodWithErrorCallback(&method_call,
+    helper_->CallVoidMethodWithErrorCallback(&method_call,
                                             callback,
                                             error_callback);
   }
@@ -91,7 +85,7 @@ class ShillManagerClientImpl : public ShillManagerClient {
                                  flimflam::kEnableTechnologyFunction);
     dbus::MessageWriter writer(&method_call);
     writer.AppendString(type);
-    helper_.CallVoidMethodWithErrorCallback(&method_call,
+    helper_->CallVoidMethodWithErrorCallback(&method_call,
                                             callback,
                                             error_callback);
   }
@@ -104,7 +98,7 @@ class ShillManagerClientImpl : public ShillManagerClient {
                                  flimflam::kDisableTechnologyFunction);
     dbus::MessageWriter writer(&method_call);
     writer.AppendString(type);
-    helper_.CallVoidMethodWithErrorCallback(&method_call,
+    helper_->CallVoidMethodWithErrorCallback(&method_call,
                                             callback,
                                             error_callback);
   }
@@ -117,7 +111,7 @@ class ShillManagerClientImpl : public ShillManagerClient {
                                  flimflam::kConfigureServiceFunction);
     dbus::MessageWriter writer(&method_call);
     ShillClientHelper::AppendServicePropertiesDictionary(&writer, properties);
-    helper_.CallObjectPathMethodWithErrorCallback(&method_call,
+    helper_->CallObjectPathMethodWithErrorCallback(&method_call,
                                                   callback,
                                                   error_callback);
   }
@@ -132,7 +126,7 @@ class ShillManagerClientImpl : public ShillManagerClient {
     dbus::MessageWriter writer(&method_call);
     writer.AppendObjectPath(dbus::ObjectPath(profile_path));
     ShillClientHelper::AppendServicePropertiesDictionary(&writer, properties);
-    helper_.CallObjectPathMethodWithErrorCallback(&method_call,
+    helper_->CallObjectPathMethodWithErrorCallback(&method_call,
                                                   callback,
                                                   error_callback);
   }
@@ -145,7 +139,7 @@ class ShillManagerClientImpl : public ShillManagerClient {
                                  flimflam::kGetServiceFunction);
     dbus::MessageWriter writer(&method_call);
     ShillClientHelper::AppendServicePropertiesDictionary(&writer, properties);
-    helper_.CallObjectPathMethodWithErrorCallback(&method_call,
+    helper_->CallObjectPathMethodWithErrorCallback(&method_call,
                                                   callback,
                                                   error_callback);
   }
@@ -163,7 +157,7 @@ class ShillManagerClientImpl : public ShillManagerClient {
     writer.AppendString(properties.device_serial);
     writer.AppendString(properties.device_ssid);
     writer.AppendString(properties.device_bssid);
-    helper_.CallBooleanMethodWithErrorCallback(
+    helper_->CallBooleanMethodWithErrorCallback(
         &method_call, callback, error_callback);
   }
 
@@ -183,7 +177,7 @@ class ShillManagerClientImpl : public ShillManagerClient {
     writer.AppendString(properties.device_ssid);
     writer.AppendString(properties.device_bssid);
     writer.AppendObjectPath(dbus::ObjectPath(service_path));
-    helper_.CallStringMethodWithErrorCallback(
+    helper_->CallStringMethodWithErrorCallback(
         &method_call, callback, error_callback);
   }
 
@@ -203,7 +197,7 @@ class ShillManagerClientImpl : public ShillManagerClient {
     writer.AppendString(properties.device_ssid);
     writer.AppendString(properties.device_bssid);
     writer.AppendString(data);
-    helper_.CallStringMethodWithErrorCallback(
+    helper_->CallStringMethodWithErrorCallback(
         &method_call, callback, error_callback);
   }
 
@@ -212,7 +206,7 @@ class ShillManagerClientImpl : public ShillManagerClient {
       const ErrorCallback& error_callback) OVERRIDE {
     dbus::MethodCall method_call(flimflam::kFlimflamManagerInterface,
                                  shill::kConnectToBestServicesFunction);
-    helper_.CallVoidMethodWithErrorCallback(&method_call,
+    helper_->CallVoidMethodWithErrorCallback(&method_call,
                                             callback,
                                             error_callback);
   }
@@ -221,9 +215,18 @@ class ShillManagerClientImpl : public ShillManagerClient {
     return NULL;
   }
 
+ protected:
+  virtual void Init(dbus::Bus* bus) OVERRIDE {
+    proxy_ =
+        bus->GetObjectProxy(flimflam::kFlimflamServiceName,
+                            dbus::ObjectPath(flimflam::kFlimflamServicePath));
+    helper_.reset(new ShillClientHelper(bus, proxy_));
+    helper_->MonitorPropertyChanged(flimflam::kFlimflamManagerInterface);
+  }
+
  private:
   dbus::ObjectProxy* proxy_;
-  ShillClientHelper helper_;
+  scoped_ptr<ShillClientHelper> helper_;
 
   DISALLOW_COPY_AND_ASSIGN(ShillManagerClientImpl);
 };
@@ -236,10 +239,9 @@ ShillManagerClient::~ShillManagerClient() {}
 
 // static
 ShillManagerClient* ShillManagerClient::Create(
-    DBusClientImplementationType type,
-    dbus::Bus* bus) {
+    DBusClientImplementationType type) {
   if (type == REAL_DBUS_CLIENT_IMPLEMENTATION)
-    return new ShillManagerClientImpl(bus);
+    return new ShillManagerClientImpl();
   DCHECK_EQ(STUB_DBUS_CLIENT_IMPLEMENTATION, type);
   return new ShillManagerClientStub();
 }
diff --git a/chromeos/dbus/shill_manager_client.h b/chromeos/dbus/shill_manager_client.h
index ce06815..c9307ca 100644
--- a/chromeos/dbus/shill_manager_client.h
+++ b/chromeos/dbus/shill_manager_client.h
@@ -9,13 +9,13 @@
 
 #include "base/basictypes.h"
 #include "chromeos/chromeos_export.h"
+#include "chromeos/dbus/dbus_client.h"
 #include "chromeos/dbus/dbus_client_implementation_type.h"
 #include "chromeos/dbus/dbus_method_call_status.h"
 #include "chromeos/dbus/shill_client_helper.h"
 
 namespace dbus {
 
-class Bus;
 class ObjectPath;
 
 }  // namespace dbus
@@ -27,7 +27,7 @@ class ShillPropertyChangedObserver;
 // ShillManagerClient is used to communicate with the Shill Manager
 // service.  All methods should be called from the origin thread which
 // initializes the DBusThreadManager instance.
-class CHROMEOS_EXPORT ShillManagerClient {
+class CHROMEOS_EXPORT ShillManagerClient : public DBusClient {
  public:
   typedef ShillClientHelper::PropertyChangedHandler PropertyChangedHandler;
   typedef ShillClientHelper::DictionaryValueCallback DictionaryValueCallback;
@@ -109,8 +109,7 @@ class CHROMEOS_EXPORT ShillManagerClient {
 
   // Factory function, creates a new instance which is owned by the caller.
   // For normal usage, access the singleton via DBusThreadManager::Get().
-  static ShillManagerClient* Create(DBusClientImplementationType type,
-                                    dbus::Bus* bus);
+  static ShillManagerClient* Create(DBusClientImplementationType type);
 
   // Adds a property changed |observer|.
   virtual void AddPropertyChangedObserver(
@@ -207,6 +206,8 @@ class CHROMEOS_EXPORT ShillManagerClient {
   virtual TestInterface* GetTestInterface() = 0;
 
  protected:
+  friend class ShillManagerClientTest;
+
   // Create() should be used instead.
   ShillManagerClient();
 
diff --git a/chromeos/dbus/shill_manager_client_stub.cc b/chromeos/dbus/shill_manager_client_stub.cc
index b601eb2..0614874 100644
--- a/chromeos/dbus/shill_manager_client_stub.cc
+++ b/chromeos/dbus/shill_manager_client_stub.cc
@@ -78,13 +78,16 @@ void AppendServicesForType(
 
 ShillManagerClientStub::ShillManagerClientStub()
     : weak_ptr_factory_(this) {
-  SetDefaultProperties();
 }
 
 ShillManagerClientStub::~ShillManagerClientStub() {}
 
 // ShillManagerClient overrides.
 
+void ShillManagerClientStub::Init(dbus::Bus* bus) {
+  SetDefaultProperties();
+}
+
 void ShillManagerClientStub::AddPropertyChangedObserver(
     ShillPropertyChangedObserver* observer) {
   observer_list_.AddObserver(observer);
diff --git a/chromeos/dbus/shill_manager_client_stub.h b/chromeos/dbus/shill_manager_client_stub.h
index 678922f..f6edc15 100644
--- a/chromeos/dbus/shill_manager_client_stub.h
+++ b/chromeos/dbus/shill_manager_client_stub.h
@@ -22,7 +22,8 @@ class ShillManagerClientStub : public ShillManagerClient,
   ShillManagerClientStub();
   virtual ~ShillManagerClientStub();
 
-  // ShillManagerClient overrides.
+  // ShillManagerClient overrides
+  virtual void Init(dbus::Bus* bus) OVERRIDE;
   virtual void AddPropertyChangedObserver(
       ShillPropertyChangedObserver* observer) OVERRIDE;
   virtual void RemovePropertyChangedObserver(
diff --git a/chromeos/dbus/shill_manager_client_unittest.cc b/chromeos/dbus/shill_manager_client_unittest.cc
index e2feccf..107458d 100644
--- a/chromeos/dbus/shill_manager_client_unittest.cc
+++ b/chromeos/dbus/shill_manager_client_unittest.cc
@@ -60,8 +60,8 @@ class ShillManagerClientTest : public ShillClientUnittestBase {
   virtual void SetUp() {
     ShillClientUnittestBase::SetUp();
     // Create a client with the mock bus.
-    client_.reset(ShillManagerClient::Create(REAL_DBUS_CLIENT_IMPLEMENTATION,
-                                             mock_bus_.get()));
+    client_.reset(ShillManagerClient::Create(REAL_DBUS_CLIENT_IMPLEMENTATION));
+    client_->Init(mock_bus_.get());
     // Run the message loop to run the signal connection result callback.
     message_loop_.RunUntilIdle();
   }
diff --git a/chromeos/dbus/shill_profile_client.cc b/chromeos/dbus/shill_profile_client.cc
index 696be7f..c0f675d 100644
--- a/chromeos/dbus/shill_profile_client.cc
+++ b/chromeos/dbus/shill_profile_client.cc
@@ -23,9 +23,8 @@ namespace {
 
 class ShillProfileClientImpl : public ShillProfileClient {
  public:
-  explicit ShillProfileClientImpl(dbus::Bus* bus);
+  ShillProfileClientImpl();
 
-  // ShillProfileClient overrides.
   virtual void AddPropertyChangedObserver(
       const dbus::ObjectPath& profile_path,
       ShillPropertyChangedObserver* observer) OVERRIDE {
@@ -37,6 +36,7 @@ class ShillProfileClientImpl : public ShillProfileClient {
       ShillPropertyChangedObserver* observer) OVERRIDE {
     GetHelper(profile_path)->RemovePropertyChangedObserver(observer);
   }
+
   virtual void GetProperties(
       const dbus::ObjectPath& profile_path,
       const DictionaryValueCallbackWithoutStatus& callback,
@@ -54,6 +54,11 @@ class ShillProfileClientImpl : public ShillProfileClient {
     return NULL;
   }
 
+ protected:
+  virtual void Init(dbus::Bus* bus) OVERRIDE {
+    bus_ = bus;
+  }
+
  private:
   typedef std::map<std::string, ShillClientHelper*> HelperMap;
 
@@ -67,8 +72,8 @@ class ShillProfileClientImpl : public ShillProfileClient {
   DISALLOW_COPY_AND_ASSIGN(ShillProfileClientImpl);
 };
 
-ShillProfileClientImpl::ShillProfileClientImpl(dbus::Bus* bus)
-    : bus_(bus),
+ShillProfileClientImpl::ShillProfileClientImpl()
+    : bus_(NULL),
       helpers_deleter_(&helpers_) {
 }
 
@@ -131,10 +136,9 @@ ShillProfileClient::~ShillProfileClient() {}
 
 // static
 ShillProfileClient* ShillProfileClient::Create(
-    DBusClientImplementationType type,
-    dbus::Bus* bus) {
+    DBusClientImplementationType type) {
   if (type == REAL_DBUS_CLIENT_IMPLEMENTATION)
-    return new ShillProfileClientImpl(bus);
+    return new ShillProfileClientImpl();
   DCHECK_EQ(STUB_DBUS_CLIENT_IMPLEMENTATION, type);
   return new ShillProfileClientStub();
 }
diff --git a/chromeos/dbus/shill_profile_client.h b/chromeos/dbus/shill_profile_client.h
index bf81afb..1529120 100644
--- a/chromeos/dbus/shill_profile_client.h
+++ b/chromeos/dbus/shill_profile_client.h
@@ -10,6 +10,7 @@
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "chromeos/chromeos_export.h"
+#include "chromeos/dbus/dbus_client.h"
 #include "chromeos/dbus/dbus_client_implementation_type.h"
 #include "chromeos/dbus/shill_client_helper.h"
 
@@ -22,7 +23,6 @@ class DictionaryValue;
 
 namespace dbus {
 
-class Bus;
 class ObjectPath;
 
 }  // namespace dbus
@@ -34,7 +34,7 @@ class ShillPropertyChangedObserver;
 // ShillProfileClient is used to communicate with the Shill Profile
 // service.  All methods should be called from the origin thread which
 // initializes the DBusThreadManager instance.
-class CHROMEOS_EXPORT ShillProfileClient {
+class CHROMEOS_EXPORT ShillProfileClient : public DBusClient {
  public:
   typedef ShillClientHelper::PropertyChangedHandler PropertyChangedHandler;
   typedef ShillClientHelper::DictionaryValueCallbackWithoutStatus
@@ -75,8 +75,7 @@ class CHROMEOS_EXPORT ShillProfileClient {
 
   // Factory function, creates a new instance which is owned by the caller.
   // For normal usage, access the singleton via DBusThreadManager::Get().
-  static ShillProfileClient* Create(DBusClientImplementationType type,
-                                    dbus::Bus* bus);
+  static ShillProfileClient* Create(DBusClientImplementationType type);
 
   // Adds a property changed |observer| for the profile at |profile_path|.
   virtual void AddPropertyChangedObserver(
@@ -113,6 +112,8 @@ class CHROMEOS_EXPORT ShillProfileClient {
   virtual TestInterface* GetTestInterface() = 0;
 
  protected:
+  friend class ShillProfileClientTest;
+
   // Create() should be used instead.
   ShillProfileClient();
 
diff --git a/chromeos/dbus/shill_profile_client_stub.cc b/chromeos/dbus/shill_profile_client_stub.cc
index ef3e74c..cfa97b7 100644
--- a/chromeos/dbus/shill_profile_client_stub.cc
+++ b/chromeos/dbus/shill_profile_client_stub.cc
@@ -40,13 +40,16 @@ void PassDictionary(
 const char ShillProfileClientStub::kSharedProfilePath[] = "/profile/default";
 
 ShillProfileClientStub::ShillProfileClientStub() {
-  AddProfile(kSharedProfilePath, std::string());
 }
 
 ShillProfileClientStub::~ShillProfileClientStub() {
   STLDeleteValues(&profiles_);
 }
 
+void ShillProfileClientStub::Init(dbus::Bus* bus) {
+  AddProfile(kSharedProfilePath, std::string());
+}
+
 void ShillProfileClientStub::AddPropertyChangedObserver(
     const dbus::ObjectPath& profile_path,
     ShillPropertyChangedObserver* observer) {
diff --git a/chromeos/dbus/shill_profile_client_stub.h b/chromeos/dbus/shill_profile_client_stub.h
index 98d8347..63a8912 100644
--- a/chromeos/dbus/shill_profile_client_stub.h
+++ b/chromeos/dbus/shill_profile_client_stub.h
@@ -21,7 +21,8 @@ class ShillProfileClientStub : public ShillProfileClient,
   ShillProfileClientStub();
   virtual ~ShillProfileClientStub();
 
-  // ShillProfileClient overrides.
+  // ShillProfileClient overrides
+  virtual void Init(dbus::Bus* bus) OVERRIDE;
   virtual void AddPropertyChangedObserver(
       const dbus::ObjectPath& profile_path,
       ShillPropertyChangedObserver* observer) OVERRIDE;
diff --git a/chromeos/dbus/shill_profile_client_unittest.cc b/chromeos/dbus/shill_profile_client_unittest.cc
index d95b62b..3352e2d 100644
--- a/chromeos/dbus/shill_profile_client_unittest.cc
+++ b/chromeos/dbus/shill_profile_client_unittest.cc
@@ -41,8 +41,8 @@ class ShillProfileClientTest : public ShillClientUnittestBase {
   virtual void SetUp() {
     ShillClientUnittestBase::SetUp();
     // Create a client with the mock bus.
-    client_.reset(ShillProfileClient::Create(REAL_DBUS_CLIENT_IMPLEMENTATION,
-                                             mock_bus_.get()));
+    client_.reset(ShillProfileClient::Create(REAL_DBUS_CLIENT_IMPLEMENTATION));
+    client_->Init(mock_bus_.get());
     // Run the message loop to run the signal connection result callback.
     message_loop_.RunUntilIdle();
   }
diff --git a/chromeos/dbus/shill_service_client.cc b/chromeos/dbus/shill_service_client.cc
index 1c42142..f058117 100644
--- a/chromeos/dbus/shill_service_client.cc
+++ b/chromeos/dbus/shill_service_client.cc
@@ -52,13 +52,11 @@ void OnGetDictionaryError(
 // The ShillServiceClient implementation.
 class ShillServiceClientImpl : public ShillServiceClient {
  public:
-  explicit ShillServiceClientImpl(dbus::Bus* bus)
-      : bus_(bus),
+  explicit ShillServiceClientImpl()
+      : bus_(NULL),
         helpers_deleter_(&helpers_) {
   }
 
-  /////////////////////////////////////
-  // ShillServiceClient overrides.
   virtual void AddPropertyChangedObserver(
       const dbus::ObjectPath& service_path,
       ShillPropertyChangedObserver* observer) OVERRIDE {
@@ -219,6 +217,11 @@ class ShillServiceClientImpl : public ShillServiceClient {
     return NULL;
   }
 
+ protected:
+  virtual void Init(dbus::Bus* bus) OVERRIDE {
+    bus_ = bus;
+  }
+
  private:
   typedef std::map<std::string, ShillClientHelper*> HelperMap;
 
@@ -252,10 +255,9 @@ ShillServiceClient::~ShillServiceClient() {}
 
 // static
 ShillServiceClient* ShillServiceClient::Create(
-    DBusClientImplementationType type,
-    dbus::Bus* bus) {
+    DBusClientImplementationType type) {
   if (type == REAL_DBUS_CLIENT_IMPLEMENTATION)
-    return new ShillServiceClientImpl(bus);
+    return new ShillServiceClientImpl();
   DCHECK_EQ(STUB_DBUS_CLIENT_IMPLEMENTATION, type);
   return new ShillServiceClientStub();
 }
diff --git a/chromeos/dbus/shill_service_client.h b/chromeos/dbus/shill_service_client.h
index 0ee87a0..6280f2c 100644
--- a/chromeos/dbus/shill_service_client.h
+++ b/chromeos/dbus/shill_service_client.h
@@ -10,6 +10,7 @@
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "chromeos/chromeos_export.h"
+#include "chromeos/dbus/dbus_client.h"
 #include "chromeos/dbus/dbus_client_implementation_type.h"
 #include "chromeos/dbus/shill_client_helper.h"
 
@@ -22,7 +23,6 @@ class DictionaryValue;
 
 namespace dbus {
 
-class Bus;
 class ObjectPath;
 
 }  // namespace dbus
@@ -33,7 +33,7 @@ namespace chromeos {
 // service.
 // All methods should be called from the origin thread which initializes the
 // DBusThreadManager instance.
-class CHROMEOS_EXPORT ShillServiceClient {
+class CHROMEOS_EXPORT ShillServiceClient : public DBusClient {
  public:
   typedef ShillClientHelper::PropertyChangedHandler PropertyChangedHandler;
   typedef ShillClientHelper::DictionaryValueCallback DictionaryValueCallback;
@@ -85,8 +85,7 @@ class CHROMEOS_EXPORT ShillServiceClient {
 
   // Factory function, creates a new instance which is owned by the caller.
   // For normal usage, access the singleton via DBusThreadManager::Get().
-  static ShillServiceClient* Create(DBusClientImplementationType type,
-                                    dbus::Bus* bus);
+  static ShillServiceClient* Create(DBusClientImplementationType type);
 
   // Adds a property changed |observer| to the service at |service_path|.
   virtual void AddPropertyChangedObserver(
@@ -184,6 +183,8 @@ class CHROMEOS_EXPORT ShillServiceClient {
   virtual TestInterface* GetTestInterface() = 0;
 
  protected:
+  friend class ShillServiceClientTest;
+
   // Create() should be used instead.
   ShillServiceClient();
 
diff --git a/chromeos/dbus/shill_service_client_stub.cc b/chromeos/dbus/shill_service_client_stub.cc
index 19dc65e..d7c28da 100644
--- a/chromeos/dbus/shill_service_client_stub.cc
+++ b/chromeos/dbus/shill_service_client_stub.cc
@@ -66,6 +66,9 @@ bool ShillServiceClientStub::IsStubPortalledWifiEnabled(
 
 // ShillServiceClient overrides.
 
+void ShillServiceClientStub::Init(dbus::Bus* bus) {
+}
+
 void ShillServiceClientStub::AddPropertyChangedObserver(
     const dbus::ObjectPath& service_path,
     ShillPropertyChangedObserver* observer) {
diff --git a/chromeos/dbus/shill_service_client_stub.h b/chromeos/dbus/shill_service_client_stub.h
index 824aa2a..4cd2964 100644
--- a/chromeos/dbus/shill_service_client_stub.h
+++ b/chromeos/dbus/shill_service_client_stub.h
@@ -29,7 +29,8 @@ class ShillServiceClientStub : public ShillServiceClient,
   CHROMEOS_EXPORT static bool IsStubPortalledWifiEnabled(
       const std::string& path);
 
-  // ShillServiceClient overrides.
+  // ShillServiceClient overrides
+  virtual void Init(dbus::Bus* bus) OVERRIDE;
   virtual void AddPropertyChangedObserver(
       const dbus::ObjectPath& service_path,
       ShillPropertyChangedObserver* observer) OVERRIDE;
diff --git a/chromeos/dbus/shill_service_client_unittest.cc b/chromeos/dbus/shill_service_client_unittest.cc
index 3d5649f..4267a45 100644
--- a/chromeos/dbus/shill_service_client_unittest.cc
+++ b/chromeos/dbus/shill_service_client_unittest.cc
@@ -33,8 +33,8 @@ class ShillServiceClientTest : public ShillClientUnittestBase {
   virtual void SetUp() {
     ShillClientUnittestBase::SetUp();
     // Create a client with the mock bus.
-    client_.reset(ShillServiceClient::Create(REAL_DBUS_CLIENT_IMPLEMENTATION,
-                                             mock_bus_.get()));
+    client_.reset(ShillServiceClient::Create(REAL_DBUS_CLIENT_IMPLEMENTATION));
+    client_->Init(mock_bus_.get());
     // Run the message loop to run the signal connection result callback.
     message_loop_.RunUntilIdle();
   }
diff --git a/chromeos/dbus/sms_client.cc b/chromeos/dbus/sms_client.cc
index ee6fb04..cd867a5 100644
--- a/chromeos/dbus/sms_client.cc
+++ b/chromeos/dbus/sms_client.cc
@@ -31,7 +31,8 @@ namespace {
 // DBusThreadManager instance.
 class SMSClientImpl : public SMSClient {
  public:
-  explicit SMSClientImpl(dbus::Bus* bus) : bus_(bus), weak_ptr_factory_(this) {}
+  SMSClientImpl() : bus_(NULL), weak_ptr_factory_(this) {}
+
   virtual ~SMSClientImpl() {}
 
   // Calls GetAll method.  |callback| is called after the method call succeeds.
@@ -49,6 +50,11 @@ class SMSClientImpl : public SMSClient {
                                   callback));
   }
 
+ protected:
+  virtual void Init(dbus::Bus* bus) OVERRIDE {
+    bus_ = bus;
+  }
+
  private:
   // Handles responses of GetAll method calls.
   void OnGetAll(const GetAllCallback& callback, dbus::Response* response) {
@@ -84,6 +90,8 @@ class SMSClientStubImpl : public SMSClient {
   SMSClientStubImpl() : weak_ptr_factory_(this) {}
   virtual ~SMSClientStubImpl() {}
 
+  virtual void Init(dbus::Bus* bus) OVERRIDE {}
+
   virtual void GetAll(const std::string& service_name,
                       const dbus::ObjectPath& object_path,
                       const GetAllCallback& callback) OVERRIDE {
@@ -131,10 +139,9 @@ SMSClient::~SMSClient() {}
 
 
 // static
-SMSClient* SMSClient::Create(DBusClientImplementationType type,
-                             dbus::Bus* bus) {
+SMSClient* SMSClient::Create(DBusClientImplementationType type) {
   if (type == REAL_DBUS_CLIENT_IMPLEMENTATION) {
-    return new SMSClientImpl(bus);
+    return new SMSClientImpl();
   }
   DCHECK_EQ(STUB_DBUS_CLIENT_IMPLEMENTATION, type);
   return new SMSClientStubImpl();
diff --git a/chromeos/dbus/sms_client.h b/chromeos/dbus/sms_client.h
index f405bad..44cfa89 100644
--- a/chromeos/dbus/sms_client.h
+++ b/chromeos/dbus/sms_client.h
@@ -10,6 +10,7 @@
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "chromeos/chromeos_export.h"
+#include "chromeos/dbus/dbus_client.h"
 #include "chromeos/dbus/dbus_client_implementation_type.h"
 
 namespace base {
@@ -17,7 +18,6 @@ class DictionaryValue;
 }
 
 namespace dbus {
-class Bus;
 class ObjectPath;
 }
 
@@ -27,7 +27,7 @@ namespace chromeos {
 // org.freedesktop.ModemManager1.SMS service.  All methods should be
 // called from the origin thread (UI thread) which initializes the
 // DBusThreadManager instance.
-class CHROMEOS_EXPORT SMSClient {
+class CHROMEOS_EXPORT SMSClient : public DBusClient {
  public:
   typedef base::Callback<void(const base::DictionaryValue& sms)> GetAllCallback;
 
@@ -35,8 +35,7 @@ class CHROMEOS_EXPORT SMSClient {
 
   // Factory function, creates a new instance and returns ownership.
   // For normal usage, access the singleton via DBusThreadManager::Get().
-  static SMSClient* Create(DBusClientImplementationType type,
-                           dbus::Bus* bus);
+  static SMSClient* Create(DBusClientImplementationType type);
 
   // Calls GetAll method.  |callback| is called after the method call succeeds.
   virtual void GetAll(const std::string& service_name,
diff --git a/chromeos/dbus/system_clock_client.cc b/chromeos/dbus/system_clock_client.cc
index b9a094e..6775c64 100644
--- a/chromeos/dbus/system_clock_client.cc
+++ b/chromeos/dbus/system_clock_client.cc
@@ -17,27 +17,12 @@ namespace chromeos {
 // The SystemClockClient implementation used in production.
 class SystemClockClientImpl : public SystemClockClient {
  public:
-  explicit SystemClockClientImpl(dbus::Bus* bus)
-      : system_clock_proxy_(NULL),
-        weak_ptr_factory_(this) {
-    system_clock_proxy_ = bus->GetObjectProxy(
-        system_clock::kSystemClockServiceName,
-        dbus::ObjectPath(system_clock::kSystemClockServicePath));
-
-    // Monitor the D-Bus signal for TimeUpdated changes.
-    system_clock_proxy_->ConnectToSignal(
-        system_clock::kSystemClockInterface,
-        system_clock::kSystemClockUpdated,
-        base::Bind(&SystemClockClientImpl::TimeUpdatedReceived,
-                   weak_ptr_factory_.GetWeakPtr()),
-        base::Bind(&SystemClockClientImpl::TimeUpdatedConnected,
-                   weak_ptr_factory_.GetWeakPtr()));
-  }
+  SystemClockClientImpl()
+      : system_clock_proxy_(NULL), weak_ptr_factory_(this) {}
 
   virtual ~SystemClockClientImpl() {
   }
 
-  // SystemClockClient overrides:
   virtual void AddObserver(Observer* observer) OVERRIDE {
     observers_.AddObserver(observer);
   }
@@ -50,6 +35,22 @@ class SystemClockClientImpl : public SystemClockClient {
     return observers_.HasObserver(observer);
   }
 
+ protected:
+  virtual void Init(dbus::Bus* bus) OVERRIDE {
+    system_clock_proxy_ = bus->GetObjectProxy(
+        system_clock::kSystemClockServiceName,
+        dbus::ObjectPath(system_clock::kSystemClockServicePath));
+
+    // Monitor the D-Bus signal for TimeUpdated changes.
+    system_clock_proxy_->ConnectToSignal(
+        system_clock::kSystemClockInterface,
+        system_clock::kSystemClockUpdated,
+        base::Bind(&SystemClockClientImpl::TimeUpdatedReceived,
+                   weak_ptr_factory_.GetWeakPtr()),
+        base::Bind(&SystemClockClientImpl::TimeUpdatedConnected,
+                   weak_ptr_factory_.GetWeakPtr()));
+  }
+
  private:
   // Called when a TimeUpdated signal is received.
   void TimeUpdatedReceived(dbus::Signal* signal) {
@@ -84,10 +85,9 @@ SystemClockClient::~SystemClockClient() {
 
 // static
 SystemClockClient* SystemClockClient::Create(
-    DBusClientImplementationType type,
-    dbus::Bus* bus) {
+    DBusClientImplementationType type) {
   if (type == REAL_DBUS_CLIENT_IMPLEMENTATION) {
-    return new SystemClockClientImpl(bus);
+    return new SystemClockClientImpl();
   }
   DCHECK_EQ(STUB_DBUS_CLIENT_IMPLEMENTATION, type);
   return new FakeSystemClockClient();
diff --git a/chromeos/dbus/system_clock_client.h b/chromeos/dbus/system_clock_client.h
index 38158da..ece1e2d 100644
--- a/chromeos/dbus/system_clock_client.h
+++ b/chromeos/dbus/system_clock_client.h
@@ -7,16 +7,13 @@
 
 #include "base/observer_list.h"
 #include "chromeos/chromeos_export.h"
+#include "chromeos/dbus/dbus_client.h"
 #include "chromeos/dbus/dbus_client_implementation_type.h"
 
-namespace dbus {
-class Bus;
-}  // namespace
-
 namespace chromeos {
 
 // SystemClockClient is used to communicate with the system clock.
-class CHROMEOS_EXPORT SystemClockClient {
+class CHROMEOS_EXPORT SystemClockClient : public DBusClient {
  public:
   // Interface for observing changes from the system clock.
   class Observer {
@@ -36,8 +33,7 @@ class CHROMEOS_EXPORT SystemClockClient {
   virtual bool HasObserver(Observer* observer) = 0;
 
   // Creates the instance.
-  static SystemClockClient* Create(DBusClientImplementationType type,
-                                   dbus::Bus* bus);
+  static SystemClockClient* Create(DBusClientImplementationType type);
 
  protected:
   // Create() should be used instead.
diff --git a/chromeos/dbus/update_engine_client.cc b/chromeos/dbus/update_engine_client.cc
index fca89aa..659d7a4 100644
--- a/chromeos/dbus/update_engine_client.cc
+++ b/chromeos/dbus/update_engine_client.cc
@@ -59,31 +59,8 @@ bool IsValidChannel(const std::string& channel) {
 // The UpdateEngineClient implementation used in production.
 class UpdateEngineClientImpl : public UpdateEngineClient {
  public:
-  explicit UpdateEngineClientImpl(dbus::Bus* bus)
-      : update_engine_proxy_(NULL),
-        last_status_(),
-        weak_ptr_factory_(this) {
-    update_engine_proxy_ = bus->GetObjectProxy(
-        update_engine::kUpdateEngineServiceName,
-        dbus::ObjectPath(update_engine::kUpdateEngineServicePath));
-
-    // Monitor the D-Bus signal for brightness changes. Only the power
-    // manager knows the actual brightness level. We don't cache the
-    // brightness level in Chrome as it will make things less reliable.
-    update_engine_proxy_->ConnectToSignal(
-        update_engine::kUpdateEngineInterface,
-        update_engine::kStatusUpdate,
-        base::Bind(&UpdateEngineClientImpl::StatusUpdateReceived,
-                   weak_ptr_factory_.GetWeakPtr()),
-        base::Bind(&UpdateEngineClientImpl::StatusUpdateConnected,
-                   weak_ptr_factory_.GetWeakPtr()));
-
-    // Get update engine status for the initial status. Update engine won't
-    // send StatusUpdate signal unless there is a status change. If chrome
-    // crashes after UPDATE_STATUS_UPDATED_NEED_REBOOT status is set,
-    // restarted chrome would not get this status. See crbug.com/154104.
-    GetUpdateEngineStatus();
-  }
+  UpdateEngineClientImpl()
+      : update_engine_proxy_(NULL), last_status_(), weak_ptr_factory_(this) {}
 
   virtual ~UpdateEngineClientImpl() {
   }
@@ -178,6 +155,30 @@ class UpdateEngineClientImpl : public UpdateEngineClient {
                    callback));
   }
 
+ protected:
+  virtual void Init(dbus::Bus* bus) OVERRIDE {
+    update_engine_proxy_ = bus->GetObjectProxy(
+        update_engine::kUpdateEngineServiceName,
+        dbus::ObjectPath(update_engine::kUpdateEngineServicePath));
+
+    // Monitor the D-Bus signal for brightness changes. Only the power
+    // manager knows the actual brightness level. We don't cache the
+    // brightness level in Chrome as it will make things less reliable.
+    update_engine_proxy_->ConnectToSignal(
+        update_engine::kUpdateEngineInterface,
+        update_engine::kStatusUpdate,
+        base::Bind(&UpdateEngineClientImpl::StatusUpdateReceived,
+                   weak_ptr_factory_.GetWeakPtr()),
+        base::Bind(&UpdateEngineClientImpl::StatusUpdateConnected,
+                   weak_ptr_factory_.GetWeakPtr()));
+
+    // Get update engine status for the initial status. Update engine won't
+    // send StatusUpdate signal unless there is a status change. If chrome
+    // crashes after UPDATE_STATUS_UPDATED_NEED_REBOOT status is set,
+    // restarted chrome would not get this status. See crbug.com/154104.
+    GetUpdateEngineStatus();
+  }
+
  private:
   void GetUpdateEngineStatus() {
     dbus::MethodCall method_call(
@@ -320,6 +321,7 @@ class UpdateEngineClientImpl : public UpdateEngineClient {
 // which does nothing.
 class UpdateEngineClientStubImpl : public UpdateEngineClient {
   // UpdateEngineClient implementation:
+  virtual void Init(dbus::Bus* bus) OVERRIDE {}
   virtual void AddObserver(Observer* observer) OVERRIDE {}
   virtual void RemoveObserver(Observer* observer) OVERRIDE {}
   virtual bool HasObserver(Observer* observer) OVERRIDE { return false; }
@@ -358,10 +360,9 @@ UpdateEngineClient::EmptyUpdateCheckCallback() {
 
 // static
 UpdateEngineClient* UpdateEngineClient::Create(
-    DBusClientImplementationType type,
-    dbus::Bus* bus) {
+    DBusClientImplementationType type) {
   if (type == REAL_DBUS_CLIENT_IMPLEMENTATION)
-    return new UpdateEngineClientImpl(bus);
+    return new UpdateEngineClientImpl();
   DCHECK_EQ(STUB_DBUS_CLIENT_IMPLEMENTATION, type);
   return new UpdateEngineClientStubImpl();
 }
diff --git a/chromeos/dbus/update_engine_client.h b/chromeos/dbus/update_engine_client.h
index 00120cb..2923c6b 100644
--- a/chromeos/dbus/update_engine_client.h
+++ b/chromeos/dbus/update_engine_client.h
@@ -8,18 +8,15 @@
 #include "base/callback.h"
 #include "base/observer_list.h"
 #include "chromeos/chromeos_export.h"
+#include "chromeos/dbus/dbus_client.h"
 #include "chromeos/dbus/dbus_client_implementation_type.h"
 
 #include <string>
 
-namespace dbus {
-class Bus;
-}
-
 namespace chromeos {
 
 // UpdateEngineClient is used to communicate with the update engine.
-class CHROMEOS_EXPORT UpdateEngineClient {
+class CHROMEOS_EXPORT UpdateEngineClient : public DBusClient {
  public:
   // Edges for state machine
   //    IDLE->CHECKING_FOR_UPDATE
@@ -123,8 +120,7 @@ class CHROMEOS_EXPORT UpdateEngineClient {
   static UpdateCheckCallback EmptyUpdateCheckCallback();
 
   // Creates the instance.
-  static UpdateEngineClient* Create(DBusClientImplementationType type,
-                                    dbus::Bus* bus);
+  static UpdateEngineClient* Create(DBusClientImplementationType type);
 
  protected:
   // Create() should be used instead.