cc: Fix missing compositor invalidations during resize

cc/resources/picture_layer_tiling_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/resources/picture_layer_tiling.h"
 
 #include <limits>
 #include <set>
 
 #include "cc/base/math_util.h"
@@ skipping 155 matching lines @@
   }
 
  protected:
   FakePictureLayerTilingClient client_;
   scoped_ptr<TestablePictureLayerTiling> tiling_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(PictureLayerTilingIteratorTest);
 };
 
+TEST_F(PictureLayerTilingIteratorTest, ResizeDeletesTiles) {
+  // Verifies that a resize deletes tiles that used to be on the edge.
+  gfx::Size tile_size(100, 100);
+  gfx::Size original_layer_size(10, 10);
+  Initialize(tile_size, 1.f, original_layer_size);
+  SetLiveRectAndVerifyTiles(gfx::Rect(original_layer_size));
+
+  // Tiling only has one tile, since its total size is less than one.
+  EXPECT_TRUE(tiling_->TileAt(0, 0));
+
+  // Stop creating tiles so that any invalidations are left as holes.
+  client_.set_allow_create_tile(false);
+
+  tiling_->SetLayerBounds(gfx::Size(200, 200));
+  EXPECT_FALSE(tiling_->TileAt(0, 0));
+}
+
 TEST_F(PictureLayerTilingIteratorTest, LiveTilesExactlyCoverLiveTileRect) {
   Initialize(gfx::Size(100, 100), 1, gfx::Size(1099, 801));
   SetLiveRectAndVerifyTiles(gfx::Rect(100, 100));
   SetLiveRectAndVerifyTiles(gfx::Rect(101, 99));
   SetLiveRectAndVerifyTiles(gfx::Rect(1099, 1));
   SetLiveRectAndVerifyTiles(gfx::Rect(1, 801));
   SetLiveRectAndVerifyTiles(gfx::Rect(1099, 1));
   SetLiveRectAndVerifyTiles(gfx::Rect(201, 800));
 }
 
@@ skipping 1503 matching lines @@
   EXPECT_FLOAT_EQ(0.f, priority.distance_to_visible);
   EXPECT_EQ(TilePriority::NOW, priority.priority_bin);
 
   priority = tiling->TileAt(1, 0)->priority(ACTIVE_TREE);
   EXPECT_FLOAT_EQ(0.f, priority.distance_to_visible);
   EXPECT_EQ(TilePriority::NOW, priority.priority_bin);
 }
 
 }  // namespace
 }  // namespace cc