Get rid of two callsites of effect_tree.FindNodeIndexFromOwningLayerId.

cc/trees/occlusion_tracker_unittest.cc

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/trees/occlusion_tracker.h"
 
 #include <stddef.h>
 
 #include "cc/animation/animation_host.h"
 #include "cc/base/filter_operation.h"
@@ skipping 60 matching lines @@
   // layer. Simple wrapper around GetUnoccludedContentRect.
   gfx::Rect UnoccludedLayerContentRect(const LayerImpl* layer,
                                        const gfx::Rect& content_rect) const {
     DCHECK(layer->visible_layer_rect().Contains(content_rect));
     return this->GetCurrentOcclusionForLayer(layer->DrawTransform())
         .GetUnoccludedContentRect(content_rect);
   }
 
   gfx::Rect UnoccludedSurfaceContentRect(const LayerImpl* layer,
                                          const gfx::Rect& content_rect) const {
-    const RenderSurfaceImpl* surface = GetRenderSurface(layer);
+    const RenderSurfaceImpl* surface =
+        GetRenderSurface(const_cast<LayerImpl*>(layer));
     return this->GetCurrentOcclusionForContributingSurface(
                      surface->draw_transform())
         .GetUnoccludedContentRect(content_rect);
   }
 };
 
 class OcclusionTrackerTest : public testing::Test {
  protected:
   explicit OcclusionTrackerTest(bool opaque_layers)
       : opaque_layers_(opaque_layers),
@@ skipping 2341 matching lines @@
     EXPECT_EQ(gfx::Rect(),
               occlusion.UnoccludedSurfaceContentRect(
                   surface, gfx::Rect(80, 70, 50, 50)));
   }
 };
 
 ALL_OCCLUSIONTRACKER_TEST(OcclusionTrackerTestUnoccludedSurfaceQuery)
 
 }  // namespace
 }  // namespace cc