cc: Don't clip tile priority visible rect to content bounds.

cc/layers/picture_layer_impl_unittest.cc

 // Copyright 2013 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/layers/picture_layer_impl.h"
 
 #include <algorithm>
 #include <limits>
 #include <set>
 #include <utility>
@@ skipping 379 matching lines @@
                                         transform_for_tile_priority,
                                         resourceless_software_draw);
   active_layer_->draw_properties().visible_content_rect = viewport;
   active_layer_->draw_properties().screen_space_transform = transform;
   active_layer_->UpdateTiles(Occlusion());
 
   gfx::Transform screen_to_view(gfx::Transform::kSkipInitialization);
   bool success = transform_for_tile_priority.GetInverse(&screen_to_view);
   EXPECT_TRUE(success);
 
+  // Note that we don't clip this to the layer bounds, since it is expected that
+  // the rect will sometimes be outside of the layer bounds. If we clip to
+  // bounds, then tile priorities will end up being incorrect in cases of fully
+  // offscreen layer.
   viewport_rect_for_tile_priority_in_view_space =
       gfx::ToEnclosingRect(MathUtil::ProjectClippedRect(
           screen_to_view, viewport_rect_for_tile_priority));
 
   // Verify the viewport rect for tile priority is used in PictureLayerImpl.
   EXPECT_EQ(active_layer_->viewport_rect_for_tile_priority(),
             viewport_rect_for_tile_priority_in_view_space);
 
-  // Interset viewport_rect_for_tile_priority_in_view_space with the layer
-  // bounds and the result should be used in PictureLayerTiling.
-  viewport_rect_for_tile_priority_in_view_space.Intersect(
-      gfx::Rect(layer_bounds));
   tilings = active_layer_->tilings();
   for (size_t i = 0; i < tilings->num_tilings(); i++) {
     PictureLayerTiling* tiling = tilings->tiling_at(i);
     EXPECT_EQ(
         tiling->GetCurrentVisibleRectForTesting(),
         gfx::ScaleToEnclosingRect(viewport_rect_for_tile_priority_in_view_space,
                                   tiling->contents_scale()));
   }
 }
 
@@ skipping 3795 matching lines @@
   ActivateTree();
   EXPECT_TRUE(active_layer_->GetRecycledTwinLayer());
   EXPECT_EQ(old_pending_layer_, active_layer_->GetRecycledTwinLayer());
 
   host_impl_.ResetRecycleTreeForTesting();
   EXPECT_FALSE(active_layer_->GetRecycledTwinLayer());
 }
 
 }  // namespace
 }  // namespace cc