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

chrome/common/chrome_switches.cc

Index: chrome/common/chrome_switches.cc
diff --git a/chrome/common/chrome_switches.cc b/chrome/common/chrome_switches.cc
index ec965cae45f9e40cb592dec6b99af703830f35ad..3fb486b5b622933e259f0d03ee2c3d22656ad758 100644
--- a/chrome/common/chrome_switches.cc
+++ b/chrome/common/chrome_switches.cc
@@ -1141,6 +1141,13 @@ const char kShowIcons[]                     = "show-icons";
 // layer compositing.
 const char kShowCompositedLayerBorders[]    = "show-composited-layer-borders";
 
+// Draws a textual dump of the compositor layer tree to help debug and study
+// layer compositing.
+const char kShowCompositedLayerTree[]       = "show-composited-layer-tree";
+
+// Draws a FPS indicator
+const char kShowFPSCounter[]                = "show-fps-counter";
+
 // Visibly render a border around paint rects in the web page to help debug
 // and study painting behavior.
 const char kShowPaintRects[]                = "show-paint-rects";