chromeos: Show onscreen bubble when brightness changes.

This adds a BrightnessLibrary class that registers to receive
notification of brightness changes from the libcros code
that I added in http://codereview.chromium.org/5640003/,
a BrightnessBubble class to control an onscreen indicator of
the current brightness level, and a BrightnessObserver class
that wires up the two.

This change depends on
http://codereview.chromium.org/5603012/, which pulls the
updated version of libcros into Chrome.

BUG=chromium-os:8473,chromium-os:4816
TEST=built and tried it

Review URL: http://codereview.chromium.org/5620004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@68879 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 30 insertions, 0 deletions

diff --git a/chrome/browser/chromeos/brightness_observer.h b/chrome/browser/chromeos/brightness_observer.h
new file mode 100644
index 0000000..ce7bc95
--- /dev/null
+++ b/chrome/browser/chromeos/brightness_observer.h
@@ -0,0 +1,30 @@
+// Copyright (c) 2010 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 CHROME_BROWSER_CHROMEOS_BRIGHTNESS_OBSERVER_H_
+#define CHROME_BROWSER_CHROMEOS_BRIGHTNESS_OBSERVER_H_
+#pragma once
+
+#include "base/basictypes.h"
+#include "chrome/browser/chromeos/cros/brightness_library.h"
+
+namespace chromeos {
+
+// This observer displays a bubble at the bottom of the screen showing the
+// current brightness level whenever the user changes it.
+class BrightnessObserver : public BrightnessLibrary::Observer {
+ public:
+  BrightnessObserver() {}
+  virtual ~BrightnessObserver() {}
+
+ private:
+  // BrightnessLibrary::Observer implementation.
+  virtual void BrightnessChanged(int level);
+
+  DISALLOW_COPY_AND_ASSIGN(BrightnessObserver);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_BRIGHTNESS_OBSERVER_H_