dbus: add support for synchronous PropertySet::Get

The existing PropertySet::Get function is asynchronous.
This CL adds the synchronous version of PropertySet::Get.
It is defined as PropertySet::GetAndBlock.

Also fix some typos and indent problems in previous
introduced SetAndBlock().

BUG=https://b.corp.google.com/u/0/issues/24131409
TEST=manually tested

Review URL: https://codereview.chromium.org/1368713002

Cr-Commit-Position: refs/heads/master@{#351185}

2 files changed, 46 insertions, 4 deletions

diff --git a/dbus/property.cc b/dbus/property.cc
index b7a0c8b..234036c 100644
--- a/dbus/property.cc
+++ b/dbus/property.cc
@@ -133,6 +133,35 @@ void PropertySet::OnGet(PropertyBase* property, GetCallback callback,
     callback.Run(response);
 }
 
+bool PropertySet::GetAndBlock(PropertyBase* property) {
+  MethodCall method_call(kPropertiesInterface, kPropertiesGet);
+  MessageWriter writer(&method_call);
+  writer.AppendString(interface());
+  writer.AppendString(property->name());
+
+  DCHECK(object_proxy_);
+  scoped_ptr<dbus::Response> response(
+      object_proxy_->CallMethodAndBlock(&method_call,
+                                        ObjectProxy::TIMEOUT_USE_DEFAULT));
+
+  if (!response.get()) {
+    LOG(WARNING) << property->name() << ": GetAndBlock: failed.";
+    return false;
+  }
+
+  MessageReader reader(response.get());
+  if (property->PopValueFromReader(&reader)) {
+    property->set_valid(true);
+    NotifyPropertyChanged(property->name());
+  } else {
+    if (property->is_valid()) {
+      property->set_valid(false);
+      NotifyPropertyChanged(property->name());
+    }
+  }
+  return true;
+}
+
 void PropertySet::GetAll() {
   MethodCall method_call(kPropertiesInterface, kPropertiesGetAll);
   MessageWriter writer(&method_call);
@@ -184,7 +213,7 @@ bool PropertySet::SetAndBlock(PropertyBase* property) {
   DCHECK(object_proxy_);
   scoped_ptr<dbus::Response> response(
       object_proxy_->CallMethodAndBlock(&method_call,
-      ObjectProxy::TIMEOUT_USE_DEFAULT));
+                                        ObjectProxy::TIMEOUT_USE_DEFAULT));
   if (response.get())
     return true;
   return false;
diff --git a/dbus/property.h b/dbus/property.h
index 940ef715d..e379f8a 100644
--- a/dbus/property.h
+++ b/dbus/property.h
@@ -259,6 +259,10 @@ class CHROME_DBUS_EXPORT PropertySet {
   virtual void OnGet(PropertyBase* property, GetCallback callback,
                      Response* response);
 
+  // The synchronous version of Get().
+  // This should never be used on an interactive thread.
+  virtual bool GetAndBlock(PropertyBase* property);
+
   // Queries the remote object for values of all properties and updates
   // initial values. Sub-classes may override to use a different D-Bus
   // method, or if the remote object does not support retrieving all
@@ -276,11 +280,13 @@ class CHROME_DBUS_EXPORT PropertySet {
   // depending on the remote object. This method may be overridden by
   // sub-classes if interfaces use different method calls.
   virtual void Set(PropertyBase* property, SetCallback callback);
-  // The sychronous version of Set().
-  virtual bool SetAndBlock(PropertyBase* property);
   virtual void OnSet(PropertyBase* property, SetCallback callback,
                      Response* response);
 
+  // The synchronous version of Set().
+  // This should never be used on an interactive thread.
+  virtual bool SetAndBlock(PropertyBase* property);
+
   // Update properties by reading an array of dictionary entries, each
   // containing a string with the name and a variant with the value, from
   // |message_reader|. Returns false if message is in incorrect format.
@@ -382,6 +388,12 @@ class CHROME_DBUS_EXPORT Property : public PropertyBase {
     property_set()->Get(this, callback);
   }
 
+  // The synchronous version of Get().
+  // This should never be used on an interactive thread.
+  virtual bool GetAndBlock() {
+    return property_set()->GetAndBlock(this);
+  }
+
   // Requests that the remote object change the property value to |value|,
   // |callback| will be called to indicate the success or failure of the
   // request, however the new value may not be available depending on the
@@ -391,7 +403,8 @@ class CHROME_DBUS_EXPORT Property : public PropertyBase {
     property_set()->Set(this, callback);
   }
 
-  // The sychronous version of Set().
+  // The synchronous version of Set().
+  // This should never be used on an interactive thread.
   virtual bool SetAndBlock(const T& value) {
     set_value_ = value;
     return property_set()->SetAndBlock(this);