cc: Reset raster scale if we didn't sync high res tiling.

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 1709 matching lines @@
   // ReleaseResources has set needs update draw properties so that the
   // new tiling gets the appropriate resolution set in ManageTilings.
   EXPECT_TRUE(host_impl_.active_tree()->needs_update_draw_properties());
   host_impl_.active_tree()->UpdateDrawProperties();
   PictureLayerTiling* high_res =
       active_layer_->tilings()->TilingAtScale(new_scale);
   ASSERT_TRUE(!!high_res);
   EXPECT_EQ(HIGH_RESOLUTION, high_res->resolution());
 }
 
+TEST_F(PictureLayerImplTest, HighResCreatedWhenBoundsShrink) {
+  SetupDefaultTrees(gfx::Size(10, 10));
+  host_impl_.active_tree()->UpdateDrawProperties();
+  EXPECT_FALSE(host_impl_.active_tree()->needs_update_draw_properties());
+
+  float result_scale_x;
+  float result_scale_y;
+  gfx::Size result_bounds;
+  active_layer_->CalculateContentsScale(0.5f,
+                                        0.5f,
+                                        0.5f,
+                                        0.5f,
+                                        false,
+                                        &result_scale_x,
+                                        &result_scale_y,
+                                        &result_bounds);
+  active_layer_->tilings()->RemoveAllTilings();
+  PictureLayerTiling* tiling = active_layer_->tilings()->AddTiling(0.5f);
+  active_layer_->tilings()->AddTiling(1.5f);
+  active_layer_->tilings()->AddTiling(0.25f);
+  tiling->set_resolution(HIGH_RESOLUTION);
+
+  // Sanity checks.
+  ASSERT_EQ(3u, active_layer_->tilings()->num_tilings());
+  ASSERT_EQ(tiling, active_layer_->tilings()->TilingAtScale(0.5f));
+
+  // Ensure we need post commit initialization on the pending layer.

[enne (OOO), 2014/05/19 22:27:36]

This is a very informative comment.  Maybe say you're simulating a commit where
this layer has changed its bounds? Normally the "post-commit init" would happen
during commit because of this change, but if you're faking the commit, setting
this flag will make it happen during UDP instead (I think?).

[vmpstr, 2014/05/19 22:46:28]

Done.

+  pending_layer_->SetNeedsPostCommitInitialization();
+  pending_layer_->set_twin_layer(NULL);
+  active_layer_->set_twin_layer(NULL);
+  EXPECT_TRUE(pending_layer_->needs_post_commit_initialization());
+
+  pending_layer_->SetBounds(gfx::Size(1, 1));
+  host_impl_.pending_tree()->UpdateDrawProperties();
+
+  // Another sanity check.
+  ASSERT_EQ(1.f, pending_layer_->MinimumContentsScale());
+
+  EXPECT_EQ(2u, pending_layer_->tilings()->num_tilings());
+  ASSERT_TRUE(pending_layer_->tilings()->TilingAtScale(1.0f));
+  EXPECT_EQ(HIGH_RESOLUTION,
+            pending_layer_->tilings()->TilingAtScale(1.0f)->resolution());
+  ASSERT_TRUE(pending_layer_->tilings()->TilingAtScale(1.5f));
+  EXPECT_EQ(NON_IDEAL_RESOLUTION,
+            pending_layer_->tilings()->TilingAtScale(1.5f)->resolution());
+}
+
 TEST_F(PictureLayerImplTest, NoLowResTilingWithGpuRasterization) {
   gfx::Size default_tile_size(host_impl_.settings().default_tile_size);
   gfx::Size layer_bounds(default_tile_size.width() * 4,
                          default_tile_size.height() * 4);
   float result_scale_x, result_scale_y;
   gfx::Size result_bounds;
 
   SetupDefaultTrees(layer_bounds);
   EXPECT_FALSE(pending_layer_->use_gpu_rasterization());
   EXPECT_EQ(0u, pending_layer_->tilings()->num_tilings());
@@ skipping 562 matching lines @@
   SetContentsScaleOnBothLayers(contents_scale,
                                device_scale,
                                page_scale,
                                maximum_animation_scale,
                                animating_transform);
   EXPECT_BOTH_EQ(HighResTiling()->contents_scale(), 1.f);
 }
 
 }  // namespace
 }  // namespace cc