cc: Don't make tiles for mask layers that are too big for a texture.

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 1148 matching lines @@
   active_layer_->SetIsMask(true);
   SetContentsScaleOnBothLayers(contents_scale,
                                device_scale,
                                page_scale,
                                maximum_animation_scale,
                                animating_transform);
   EXPECT_BOTH_EQ(HighResTiling()->contents_scale(), contents_scale);
   EXPECT_BOTH_EQ(num_tilings(), 1u);
 }
 
+TEST_F(PictureLayerImplTest, HugeMasksDontGetTiles) {
+  gfx::Size tile_size(host_impl_.settings().default_tile_size);
+  SetupDefaultTrees(tile_size);
+
+  float contents_scale = 1.f;
+  float device_scale = 1.f;
+  float page_scale = 1.f;
+  float maximum_animation_scale = 1.f;
+  bool animating_transform = false;
+
+  pending_layer_->SetIsMask(true);
+  active_layer_->SetIsMask(true);
+  SetContentsScaleOnBothLayers(contents_scale,
+                               device_scale,
+                               page_scale,
+                               maximum_animation_scale,
+                               animating_transform);
+  EXPECT_BOTH_EQ(HighResTiling()->contents_scale(), contents_scale);
+  EXPECT_BOTH_EQ(num_tilings(), 1u);
+
+  pending_layer_->HighResTiling()->CreateAllTilesForTesting();
+  active_layer_->HighResTiling()->CreateAllTilesForTesting();
+
+  // Mask layers have a tiling with a single tile in it.
+  EXPECT_BOTH_EQ(HighResTiling()->AllTilesForTesting().size(), 1u);
+
+  ResetTilingsAndRasterScales();
+
+  int max_texture_size = host_impl_.GetRendererCapabilities().max_texture_size;
+  EXPECT_LE(pending_layer_->bounds().width(), max_texture_size);
+  EXPECT_LE(pending_layer_->bounds().height(), max_texture_size);
+  EXPECT_LE(active_layer_->bounds().width(), max_texture_size);
+  EXPECT_LE(active_layer_->bounds().height(), max_texture_size);
+
+  pending_layer_->SetBounds(gfx::Size(max_texture_size + 1, 10));
+  active_layer_->SetBounds(gfx::Size(10, max_texture_size + 1));
+
+  SetContentsScaleOnBothLayers(contents_scale,
+                               device_scale,
+                               page_scale,
+                               maximum_animation_scale,
+                               animating_transform);
+  EXPECT_BOTH_EQ(HighResTiling()->contents_scale(), contents_scale);
+  EXPECT_BOTH_EQ(num_tilings(), 1u);
+
+  pending_layer_->HighResTiling()->CreateAllTilesForTesting();
+  active_layer_->HighResTiling()->CreateAllTilesForTesting();
+
+  // Mask layers have a tiling, but there should be no tiles in it.
+  EXPECT_BOTH_EQ(HighResTiling()->AllTilesForTesting().size(), 1u);

[enne (OOO), 2014/09/05 17:41:46]

"there should be no tiles" but 1u?

Also, can you call ContentsResourceId inside this unit test before and after to
make sure it returns non-zero and zero, respectively?

[danakj, 2014/09/05 22:09:52]

Oh snap, thanks. My test is bad and I feel bad.
Ya!

+}
+
 TEST_F(PictureLayerImplTest, ReleaseResources) {
   gfx::Size tile_size(400, 400);
   gfx::Size layer_bounds(1300, 1900);
 
   scoped_refptr<FakePicturePileImpl> pending_pile =
       FakePicturePileImpl::CreateFilledPile(tile_size, layer_bounds);
   scoped_refptr<FakePicturePileImpl> active_pile =
       FakePicturePileImpl::CreateFilledPile(tile_size, layer_bounds);
 
   SetupTrees(pending_pile, active_pile);
@@ skipping 2942 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