cc: Fix missing compositor invalidations during resize

cc/resources/picture_layer_tiling_unittest.cc

Index: cc/resources/picture_layer_tiling_unittest.cc
diff --git a/cc/resources/picture_layer_tiling_unittest.cc b/cc/resources/picture_layer_tiling_unittest.cc
index 976ed6b14a2693269570901de40df32061143f65..e1eddd7d40ebfab471d8234a670eff5bc9b3a704 100644
--- a/cc/resources/picture_layer_tiling_unittest.cc
+++ b/cc/resources/picture_layer_tiling_unittest.cc
@@ -173,6 +173,23 @@ class PictureLayerTilingIteratorTest : public testing::Test {
   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));