Add flag to switch Chromium OS Bluetooth backend

This flag is passed by the OS session manager when it detects the
newer Bluetooth backend is being used, and selects the alternate
implementation of BluetoothAdapter.

BUG=chromium-os:38832
TEST=started chrome with/without flag


Review URL: https://chromiumcodereview.appspot.com/12660002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@187080 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index 572e592..883a654 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -1263,6 +1263,15 @@
     SINGLE_VALUE_TYPE(switches::kDisableGestureRequirementForMediaPlayback)
   },
 #endif
+#if defined(OS_CHROMEOS)
+  {
+    "enable-experimental-bluetooth",
+    IDS_FLAGS_ENABLE_EXPERIMENTAL_BLUETOOTH_NAME,
+    IDS_FLAGS_ENABLE_EXPERIMENTAL_BLUETOOTH_DESCRIPTION,
+    kOsCrOS,
+    SINGLE_VALUE_TYPE(chromeos::switches::kEnableExperimentalBluetooth)
+  },
+#endif
 };
 
 const Experiment* experiments = kExperiments;