chromeos: Make CheckIdleStateIsLocked() query D-Bus client.

Make the Chrome OS implementation of
CheckIdleStateIsLocked() (used by the chrome.idle API) get
the lock state from chromeos::SessionManagerClient instead
of depending on ash::SessionStateDelegate (which reaches
into chrome/browser/chromeos/login/). This makes it possible
for the idle code to be later moved under ui/base/ instead
of living in chrome/browser/, permitting the chrome.idle API
to be moved from chrome/ to extensions/.

As part of this, make SessionManagerClient cache the
most-recently-received-from-session_manager screen-lock
state. Previously it just passed state updates to its
observers, but the idle functions lack a class that can
register itself as an observer.

BUG=446320

Review URL: https://codereview.chromium.org/852453005

Cr-Commit-Position: refs/heads/master@{#311333}

8 files changed, 31 insertions, 8 deletions

diff --git a/chrome/browser/chromeos/settings/device_settings_test_helper.cc b/chrome/browser/chromeos/settings/device_settings_test_helper.cc
index 3704edb..712b356 100644
--- a/chrome/browser/chromeos/settings/device_settings_test_helper.cc
+++ b/chrome/browser/chromeos/settings/device_settings_test_helper.cc
@@ -104,6 +104,8 @@ bool DeviceSettingsTestHelper::HasObserver(const Observer* observer) const {
   return false;
 }
 
+bool DeviceSettingsTestHelper::IsScreenLocked() const { return false; }
+
 void DeviceSettingsTestHelper::EmitLoginPromptVisible() {}
 
 void DeviceSettingsTestHelper::RestartJob(int pid,
diff --git a/chrome/browser/chromeos/settings/device_settings_test_helper.h b/chrome/browser/chromeos/settings/device_settings_test_helper.h
index 14147a1..74a198f 100644
--- a/chrome/browser/chromeos/settings/device_settings_test_helper.h
+++ b/chrome/browser/chromeos/settings/device_settings_test_helper.h
@@ -88,6 +88,7 @@ class DeviceSettingsTestHelper : public SessionManagerClient {
   virtual void AddObserver(Observer* observer) override;
   virtual void RemoveObserver(Observer* observer) override;
   virtual bool HasObserver(const Observer* observer) const override;
+  virtual bool IsScreenLocked() const override;
   virtual void EmitLoginPromptVisible() override;
   virtual void RestartJob(int pid, const std::string& command_line) override;
   virtual void StartSession(const std::string& user_email) override;
diff --git a/chrome/browser/idle_chromeos.cc b/chrome/browser/idle_chromeos.cc
index 9505d05..7c289a7 100644
--- a/chrome/browser/idle_chromeos.cc
+++ b/chrome/browser/idle_chromeos.cc
@@ -4,9 +4,9 @@
 
 #include "chrome/browser/idle.h"
 
-#include "ash/session/session_state_delegate.h"
-#include "ash/shell.h"
 #include "base/time/time.h"
+#include "chromeos/dbus/dbus_thread_manager.h"
+#include "chromeos/dbus/session_manager_client.h"
 #include "ui/base/user_activity/user_activity_detector.h"
 
 void CalculateIdleTime(IdleTimeCallback notify) {
@@ -16,9 +16,6 @@ void CalculateIdleTime(IdleTimeCallback notify) {
 }
 
 bool CheckIdleStateIsLocked() {
-#if defined(USE_ATHENA)
-  return false;
-#else
-  return ash::Shell::GetInstance()->session_state_delegate()->IsScreenLocked();
-#endif
+  return chromeos::DBusThreadManager::Get()->GetSessionManagerClient()->
+      IsScreenLocked();
 }
diff --git a/chromeos/dbus/fake_session_manager_client.cc b/chromeos/dbus/fake_session_manager_client.cc
index f16e9c6..27fe2df 100644
--- a/chromeos/dbus/fake_session_manager_client.cc
+++ b/chromeos/dbus/fake_session_manager_client.cc
@@ -39,6 +39,10 @@ bool FakeSessionManagerClient::HasObserver(const Observer* observer) const {
   return observers_.HasObserver(observer);
 }
 
+bool FakeSessionManagerClient::IsScreenLocked() const {
+  return false;
+}
+
 void FakeSessionManagerClient::EmitLoginPromptVisible() {
 }
 
diff --git a/chromeos/dbus/fake_session_manager_client.h b/chromeos/dbus/fake_session_manager_client.h
index c0e53aa..3d11691 100644
--- a/chromeos/dbus/fake_session_manager_client.h
+++ b/chromeos/dbus/fake_session_manager_client.h
@@ -29,6 +29,7 @@ class FakeSessionManagerClient : public SessionManagerClient {
   virtual void AddObserver(Observer* observer) override;
   virtual void RemoveObserver(Observer* observer) override;
   virtual bool HasObserver(const Observer* observer) const override;
+  virtual bool IsScreenLocked() const override;
   virtual void EmitLoginPromptVisible() override;
   virtual void RestartJob(int pid, const std::string& command_line) override;
   virtual void StartSession(const std::string& user_email) override;
diff --git a/chromeos/dbus/mock_session_manager_client.h b/chromeos/dbus/mock_session_manager_client.h
index cdc5d6d..3a88e52 100644
--- a/chromeos/dbus/mock_session_manager_client.h
+++ b/chromeos/dbus/mock_session_manager_client.h
@@ -22,6 +22,7 @@ class MockSessionManagerClient : public SessionManagerClient {
   MOCK_METHOD1(AddObserver, void(Observer*));
   MOCK_METHOD1(RemoveObserver, void(Observer*));
   MOCK_CONST_METHOD1(HasObserver, bool(const Observer*));
+  MOCK_CONST_METHOD0(IsScreenLocked, bool(void));
   MOCK_METHOD0(EmitLoginPromptVisible, void(void));
   MOCK_METHOD2(RestartJob, void(int, const std::string&));
   MOCK_METHOD1(StartSession, void(const std::string&));
diff --git a/chromeos/dbus/session_manager_client.cc b/chromeos/dbus/session_manager_client.cc
index 6dc2dce..27adf8b 100644
--- a/chromeos/dbus/session_manager_client.cc
+++ b/chromeos/dbus/session_manager_client.cc
@@ -66,6 +66,7 @@ class SessionManagerClientImpl : public SessionManagerClient {
  public:
   SessionManagerClientImpl()
       : session_manager_proxy_(NULL),
+        screen_is_locked_(false),
         weak_ptr_factory_(this) {}
 
   virtual ~SessionManagerClientImpl() {
@@ -88,6 +89,8 @@ class SessionManagerClientImpl : public SessionManagerClient {
     return observers_.HasObserver(observer);
   }
 
+  virtual bool IsScreenLocked() const override { return screen_is_locked_; }
+
   virtual void EmitLoginPromptVisible() override {
     SimpleMethodCallToSessionManager(
         login_manager::kSessionManagerEmitLoginPromptVisible);
@@ -517,10 +520,12 @@ class SessionManagerClientImpl : public SessionManagerClient {
   }
 
   void ScreenIsLockedReceived(dbus::Signal* signal) {
+    screen_is_locked_ = true;
     FOR_EACH_OBSERVER(Observer, observers_, ScreenIsLocked());
   }
 
   void ScreenIsUnlockedReceived(dbus::Signal* signal) {
+    screen_is_locked_ = false;
     FOR_EACH_OBSERVER(Observer, observers_, ScreenIsUnlocked());
   }
 
@@ -568,6 +573,9 @@ class SessionManagerClientImpl : public SessionManagerClient {
   scoped_ptr<BlockingMethodCaller> blocking_method_caller_;
   ObserverList<Observer> observers_;
 
+  // Most recent screen-lock state received from session_manager.
+  bool screen_is_locked_;
+
   // Note: This should remain the last member so it'll be destroyed and
   // invalidate its weak pointers before any other members are destroyed.
   base::WeakPtrFactory<SessionManagerClientImpl> weak_ptr_factory_;
@@ -579,7 +587,7 @@ class SessionManagerClientImpl : public SessionManagerClient {
 // which does nothing.
 class SessionManagerClientStubImpl : public SessionManagerClient {
  public:
-  SessionManagerClientStubImpl() : delegate_(NULL) {}
+  SessionManagerClientStubImpl() : delegate_(NULL), screen_is_locked_(false) {}
   virtual ~SessionManagerClientStubImpl() {}
 
   // SessionManagerClient overrides
@@ -596,6 +604,7 @@ class SessionManagerClientStubImpl : public SessionManagerClient {
   virtual bool HasObserver(const Observer* observer) const override {
     return observers_.HasObserver(observer);
   }
+  virtual bool IsScreenLocked() const override { return screen_is_locked_; }
   virtual void EmitLoginPromptVisible() override {}
   virtual void RestartJob(int pid, const std::string& command_line) override {}
   virtual void StartSession(const std::string& user_email) override {}
@@ -608,9 +617,11 @@ class SessionManagerClientStubImpl : public SessionManagerClient {
       delegate_->LockScreenForStub();
   }
   virtual void NotifyLockScreenShown() override {
+    screen_is_locked_ = true;
     FOR_EACH_OBSERVER(Observer, observers_, ScreenIsLocked());
   }
   virtual void NotifyLockScreenDismissed() override {
+    screen_is_locked_ = false;
     FOR_EACH_OBSERVER(Observer, observers_, ScreenIsUnlocked());
   }
   virtual void RetrieveActiveSessions(
@@ -732,6 +743,7 @@ class SessionManagerClientStubImpl : public SessionManagerClient {
   StubDelegate* delegate_;  // Weak pointer; may be NULL.
   ObserverList<Observer> observers_;
   std::string device_policy_;
+  bool screen_is_locked_;
 
   DISALLOW_COPY_AND_ASSIGN(SessionManagerClientStubImpl);
 };
diff --git a/chromeos/dbus/session_manager_client.h b/chromeos/dbus/session_manager_client.h
index 758f26e..dd6048d 100644
--- a/chromeos/dbus/session_manager_client.h
+++ b/chromeos/dbus/session_manager_client.h
@@ -65,6 +65,11 @@ class CHROMEOS_EXPORT SessionManagerClient : public DBusClient {
   virtual void RemoveObserver(Observer* observer) = 0;
   virtual bool HasObserver(const Observer* observer) const = 0;
 
+  // Returns the most recent screen-lock state received from session_manager.
+  // This mirrors the last Observer::ScreenIsLocked() or ScreenIsUnlocked()
+  // call.
+  virtual bool IsScreenLocked() const = 0;
+
   // Kicks off an attempt to emit the "login-prompt-visible" upstart signal.
   virtual void EmitLoginPromptVisible() = 0;