Enable disabling WebCore::GraphicsContext in telemetry.

cc/layers/content_layer_client.h

Index: cc/layers/content_layer_client.h
diff --git a/cc/layers/content_layer_client.h b/cc/layers/content_layer_client.h
index 6a77dab532e29c9b70f6075e2bc3068edc247380..8271cd5e27f1711d2e2e7ba8ee38c2b39d82c7ea 100644
--- a/cc/layers/content_layer_client.h
+++ b/cc/layers/content_layer_client.h
@@ -18,9 +18,15 @@ namespace cc {
 
 class CC_EXPORT ContentLayerClient {
  public:
+  enum GraphicsContextStatus {
+    GRAPHICS_CONTEXT_DISABLED,
+    GRAPHICS_CONTEXT_ENABLED
+  };
+
   virtual void PaintContents(SkCanvas* canvas,
                              const gfx::Rect& clip,
-                             gfx::RectF* opaque) = 0;
+                             gfx::RectF* opaque,
+                             GraphicsContextStatus gc_status) = 0;
 
   // Called by the content layer during the update phase.
   // If the client paints LCD text, it may want to invalidate the layer.