Remove dead paint flush tracking code.

content/renderer/render_widget_fullscreen_pepper.cc

Index: content/renderer/render_widget_fullscreen_pepper.cc
diff --git a/content/renderer/render_widget_fullscreen_pepper.cc b/content/renderer/render_widget_fullscreen_pepper.cc
index 7038716ed40f4f2077177a54eaf89c00092b5959..6436a25e4b73196ddd2646fa7c4284ef175b3a07 100644
--- a/content/renderer/render_widget_fullscreen_pepper.cc
+++ b/content/renderer/render_widget_fullscreen_pepper.cc
@@ -348,9 +348,6 @@ void RenderWidgetFullscreenPepper::DidInitiatePaint() {
     plugin_->ViewInitiatedPaint();
 }
 
-void RenderWidgetFullscreenPepper::DidFlushPaint() {
-}
-
 void RenderWidgetFullscreenPepper::Close() {
   // If the fullscreen window is closed (e.g. user pressed escape), reset to
   // normal mode.