cc: Make 1/4th default low res scale.

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 <utility>
 
 #include "cc/layers/append_quads_data.h"
 #include "cc/layers/picture_layer.h"
@@ skipping 659 matching lines @@
 
   // Stop animating, low res gets created.
   animating_transform = false;
   SetContentsScaleOnBothLayers(
       contents_scale, device_scale, page_scale, animating_transform);
   EXPECT_BOTH_EQ(HighResTiling()->contents_scale(), 1.f);
   EXPECT_BOTH_EQ(LowResTiling()->contents_scale(), low_res_factor);
   EXPECT_BOTH_EQ(num_tilings(), 2u);
 
   // Page scale animation, new high res, but not new low res because animating.
-  contents_scale = 4.f;
-  page_scale = 4.f;
+  contents_scale = 2.f;

[vmpstr, 2013/08/05 18:41:27]

This change is here since with the new low res contents scale of 0.25, it just
happens to look like going 4 -> 1 creates a new tiling, where in reality the old
high res becomes the new low res (with no new tiling created)

+  page_scale = 2.f;
   animating_transform = true;
   SetContentsScaleOnBothLayers(
       contents_scale, device_scale, page_scale, animating_transform);
-  EXPECT_BOTH_EQ(HighResTiling()->contents_scale(), 4.f);
+  EXPECT_BOTH_EQ(HighResTiling()->contents_scale(), 2.f);
   EXPECT_BOTH_EQ(LowResTiling()->contents_scale(), low_res_factor);
   EXPECT_BOTH_EQ(num_tilings(), 3u);
 
   // Stop animating, new low res gets created for final page scale.
   animating_transform = false;
   SetContentsScaleOnBothLayers(
       contents_scale, device_scale, page_scale, animating_transform);
-  EXPECT_BOTH_EQ(HighResTiling()->contents_scale(), 4.f);
-  EXPECT_BOTH_EQ(LowResTiling()->contents_scale(), 4.f * low_res_factor);
+  EXPECT_BOTH_EQ(HighResTiling()->contents_scale(), 2.f);
+  EXPECT_BOTH_EQ(LowResTiling()->contents_scale(), 2.f * low_res_factor);
   EXPECT_BOTH_EQ(num_tilings(), 4u);
 }
 
 TEST_F(PictureLayerImplTest, DontAddLowResForSmallLayers) {
   gfx::Size tile_size(host_impl_.settings().default_tile_size);
   SetupDefaultTrees(tile_size);
 
   float low_res_factor = host_impl_.settings().low_res_contents_scale_factor;
   float device_scale = 1.f;
   float page_scale = 1.f;
@@ skipping 331 matching lines @@
   active_layer_ = static_cast<FakePictureLayerImpl*>(
       host_impl_.active_tree()->LayerById(id_));
 
   EXPECT_EQ(0u, active_layer_->num_tilings());
   EXPECT_EQ(!default_lcd_text_setting, active_layer_->is_using_lcd_text());
   EXPECT_FALSE(active_layer_->needs_post_commit_initialization());
 }
 
 }  // namespace
 }  // namespace cc