chromeos: Add operations to monitor the screen orientation.

content/browser/sensors/sensors_source_chromeos.h

+// Copyright (c) 2011 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 CONTENT_BROWSER_CHROMEOS_SENSORS_SOURCE_CHROMEOS_H_
+#define CONTENT_BROWSER_CHROMEOS_SENSORS_SOURCE_CHROMEOS_H_
+
+#include "base/memory/ref_counted.h"
+
+#include <string>
+
+namespace dbus {
+class Bus;
+class ObjectProxy;
+class Signal;
+}  // namespace
+
+namespace sensors {
+
+// Creates and manages a dbus signal receiver for device orientation changes,
+// and eventually receives data for other motion-related sensors.
+class SensorsSourceChromeos
+    : public base::RefCountedThreadSafe<SensorsSourceChromeos> {
+ public:
+  SensorsSourceChromeos();
+
+  bool Init();

[satorux1, 2011/09/12 19:46:38]

Function comment is missing. This may be obvious but would be nice add a brief
one-line comment, like "Initializes the sensor source. Returns true on success".

http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml?showone=Functi...

Every function declaration should have comments immediately preceding it that
describe what the function does and how to use it. These comments should be
descriptive ("Opens the file") rather than imperative ("Open the file"); 

[cwolfe, 2011/09/12 21:17:36]

Done.

+  void Stop();
+
+ private:
+  friend class base::RefCountedThreadSafe<SensorsSourceChromeos>;
+  virtual ~SensorsSourceChromeos();
+
+  void OrientationChangedReceived(dbus::Signal* signal);
+  void OrientationChangedConnected(const std::string& iface_name,

[satorux1, 2011/09/12 19:46:38]

iface ->interface? We generally eschew abbreviation.

http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml?showone=Genera...

[cwolfe, 2011/09/12 21:17:36]

Done.

+                                   const std::string& signal_name,
+                                   bool success);

[satorux1, 2011/09/12 19:46:38]

Ditto. Function comments are missing. One-line comments would suffice.

[cwolfe, 2011/09/12 21:17:36]

Done.

+
+  scoped_refptr<dbus::Bus> bus_;
+  dbus::ObjectProxy* sensors_proxy_;
+
+  DISALLOW_COPY_AND_ASSIGN(SensorsSourceChromeos);
+};
+
+}  // namespace sensors
+
+#endif  // CONTENT_BROWSER_CHROMEOS_SENSORS_SOURCE_CHROMEOS_H_