Implement device_orientation::Provider.

Provider provides its registered observers with device orientation data
by finding and polling a DataFetcher on a background thread.

BUG=44654
TEST=unit_tests --gtest_filter="DeviceOrientationProviderTest.*"

Review URL: http://codereview.chromium.org/3136008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@57036 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/chrome_browser.gypi b/chrome/chrome_browser.gypi
index f8fae727..882ea70 100644
--- a/chrome/chrome_browser.gypi
+++ b/chrome/chrome_browser.gypi
@@ -1118,11 +1118,14 @@
         'browser/default_encoding_combo_model.h',
         'browser/defaults.cc',
         'browser/defaults.h',
+        'browser/device_orientation/data_fetcher.h',
         'browser/device_orientation/dispatcher_host.cc',
         'browser/device_orientation/dispatcher_host.h',
         'browser/device_orientation/orientation.h',
         'browser/device_orientation/provider.cc',
         'browser/device_orientation/provider.h',
+        'browser/device_orientation/provider_impl.cc',
+        'browser/device_orientation/provider_impl.h',
         'browser/diagnostics/diagnostics_main.cc',
         'browser/diagnostics/diagnostics_main.h',
         'browser/diagnostics/diagnostics_model.h',