cc: Rename LayerImpl::render_surface to GetRenderSurface

cc/trees/occlusion_tracker_unittest.cc

Index: cc/trees/occlusion_tracker_unittest.cc
diff --git a/cc/trees/occlusion_tracker_unittest.cc b/cc/trees/occlusion_tracker_unittest.cc
index 8c3120d841ac31ea9b5082300ec659f7f3f50ebc..2e0d1b6d92a744d0326ffc27ea0ca3352c62b7af 100644
--- a/cc/trees/occlusion_tracker_unittest.cc
+++ b/cc/trees/occlusion_tracker_unittest.cc
@@ -77,7 +77,7 @@ class TestOcclusionTrackerWithClip : public TestOcclusionTracker {
 
   gfx::Rect UnoccludedSurfaceContentRect(const LayerImpl* layer,
                                          const gfx::Rect& content_rect) const {
-    RenderSurfaceImpl* surface = layer->render_surface();
+    RenderSurfaceImpl* surface = layer->GetRenderSurface();
     return this->GetCurrentOcclusionForContributingSurface(
                      surface->draw_transform())
         .GetUnoccludedContentRect(content_rect);