Do not clip inside OcclusionTracker.

cc/trees/occlusion_tracker.h

Index: cc/trees/occlusion_tracker.h
diff --git a/cc/trees/occlusion_tracker.h b/cc/trees/occlusion_tracker.h
index 1b86d72d103073e79f48a8dcd67278380a662701..e21cb757648dcf0ef155ef4d208ec50a87d6aba8 100644
--- a/cc/trees/occlusion_tracker.h
+++ b/cc/trees/occlusion_tracker.h
@@ -48,27 +48,21 @@ class CC_EXPORT OcclusionTrackerBase {
   // Returns true if the given rect in content space for a layer is fully
   // occluded in either screen space or the layer's target surface.
   // |render_target| is the contributing layer's render target, and
-  // |draw_transform|, |transformsToTargetKnown| and |clippedRectInTarget| are
-  // relative to that.
+  // |draw_transform| and |impl_draw_transform_is_unknown| are relative to that.
   bool Occluded(const LayerType* render_target,
                 gfx::Rect content_rect,
                 const gfx::Transform& draw_transform,
-                bool impl_draw_transform_is_unknown,
-                bool is_clipped,
-                gfx::Rect clip_rect_in_target) const;
+                bool impl_draw_transform_is_unknown) const;
 
   // Gives an unoccluded sub-rect of |content_rect| in the content space of a
   // layer. Used when considering occlusion for a layer that paints/draws
   // something. |render_target| is the contributing layer's render target, and
-  // |draw_transform|, |transformsToTargetKnown| and |clippedRectInTarget| are
-  // relative to that.
+  // |draw_transform| and |impl_draw_transform_is_unknown| are relative to that.
   gfx::Rect UnoccludedContentRect(
       const LayerType* render_target,
       gfx::Rect content_rect,
       const gfx::Transform& draw_transform,
-      bool impl_draw_transform_is_unknown,
-      bool is_clipped,
-      gfx::Rect clip_rect_in_target) const;
+      bool impl_draw_transform_is_unknown) const;
 
   // Gives an unoccluded sub-rect of |content_rect| in the content space of the
   // render_target owned by the layer. Used when considering occlusion for a