Add command line switches and about:flag to enable FPS indicator and compositor layer tree.

Intentionally did not add a flag for compositor-layer-tree. Can add one if we feel it is truly useful.

BUG=
TEST=

Review URL: http://codereview.chromium.org/6581004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@77163 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index 4d59c635..b492c49 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -156,6 +156,13 @@
     SINGLE_VALUE_TYPE(switches::kShowCompositedLayerBorders)
   },
   {
+    "show-fps-counter",
+    IDS_FLAGS_SHOW_FPS_COUNTER,
+    IDS_FLAGS_SHOW_FPS_COUNTER_DESCRIPTION,
+    kOsAll,
+    SINGLE_VALUE_TYPE(switches::kShowFPSCounter)
+  },
+  {
     "gpu-canvas-2d",  // FLAGS:RECORD_UMA
     IDS_FLAGS_ACCELERATED_CANVAS_2D_NAME,
     IDS_FLAGS_ACCELERATED_CANVAS_2D_DESCRIPTION,