Vertical GlowEffect shown on about:blank page in low end devices

cc/trees/layer_tree_host_impl_unittest.cc

 // Copyright 2011 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/trees/layer_tree_host_impl.h"
 
 #include <cmath>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 79 matching lines @@
         current_limit_bytes_(0),
         current_priority_cutoff_value_(0) {
     media::InitializeMediaLibraryForTesting();
   }
 
   LayerTreeSettings DefaultSettings() {
     LayerTreeSettings settings;
     settings.minimum_occlusion_tracking_size = gfx::Size();
     settings.impl_side_painting = true;
     settings.texture_id_allocation_chunk_size = 1;
+    settings.report_overscroll_only_for_scrollable_axes = true;
     return settings;
   }
 
   virtual void SetUp() OVERRIDE {
     CreateHostImpl(DefaultSettings(), CreateOutputSurface());
   }
 
   virtual void TearDown() OVERRIDE {}
 
   virtual void UpdateRendererCapabilitiesOnImplThread() OVERRIDE {}
@@ skipping 3054 matching lines @@
   DrawFrame();
   EXPECT_EQ(gfx::Vector2dF(), host_impl_->accumulated_root_overscroll());
 
   // Even though the layer can't scroll the overscroll still happens.
   EXPECT_EQ(InputHandler::ScrollStarted,
             host_impl_->ScrollBegin(gfx::Point(), InputHandler::Wheel));
   host_impl_->ScrollBy(gfx::Point(), gfx::Vector2d(0, 10));
   EXPECT_EQ(gfx::Vector2dF(0, 10), host_impl_->accumulated_root_overscroll());
 }
 
+TEST_F(LayerTreeHostImplTest, NoOverscrollOnFractionalDeviceScale) {
+  gfx::Size surface_size(980, 1439);
+  gfx::Size content_size(980, 1438);
+  float device_scale_factor = 1.5f;
+  scoped_ptr<LayerImpl> root_clip =
+      LayerImpl::Create(host_impl_->active_tree(), 3);
+  scoped_ptr<LayerImpl> root =
+      CreateScrollableLayer(1, content_size, root_clip.get());
+  root->SetIsContainerForFixedPositionLayers(true);
+  scoped_ptr<LayerImpl> child =
+      CreateScrollableLayer(2, content_size, root_clip.get());
+  root->scroll_clip_layer()->SetBounds(gfx::Size(320, 469));
+  host_impl_->active_tree()->SetPageScaleFactorAndLimits(
+      0.326531f, 0.326531f, 5.f);
+  host_impl_->active_tree()->SetPageScaleDelta(1.f);
+  child->SetScrollClipLayer(Layer::INVALID_ID);
+  root->AddChild(child.Pass());
+  root_clip->AddChild(root.Pass());
+
+  host_impl_->SetViewportSize(surface_size);
+  host_impl_->SetDeviceScaleFactor(device_scale_factor);
+  host_impl_->active_tree()->SetRootLayer(root_clip.Pass());
+  host_impl_->active_tree()->SetViewportLayersFromIds(3, 1, Layer::INVALID_ID);
+  host_impl_->active_tree()->DidBecomeActive();
+  DrawFrame();
+  {
+    // Horizontal & Vertical GlowEffect should not be applied when
+    // content size is less then view port size. For Example Horizontal &
+    // vertical GlowEffect should not be applied in about:blank page.
+    EXPECT_EQ(InputHandler::ScrollStarted,
+              host_impl_->ScrollBegin(gfx::Point(0, 0), InputHandler::Wheel));
+    host_impl_->ScrollBy(gfx::Point(), gfx::Vector2dF(0, -1));
+    EXPECT_EQ(gfx::Vector2dF().ToString(),
+              host_impl_->accumulated_root_overscroll().ToString());
+
+    host_impl_->ScrollEnd();
+  }
+}
+
 TEST_F(LayerTreeHostImplTest, NoOverscrollWhenNotAtEdge) {
   gfx::Size surface_size(100, 100);
   gfx::Size content_size(200, 200);
   scoped_ptr<LayerImpl> root_clip =
       LayerImpl::Create(host_impl_->active_tree(), 3);
   scoped_ptr<LayerImpl> root =
       CreateScrollableLayer(1, content_size, root_clip.get());
   root->SetIsContainerForFixedPositionLayers(true);
   scoped_ptr<LayerImpl> child =
       CreateScrollableLayer(2, content_size, root_clip.get());
@@ skipping 3088 matching lines @@
   EXPECT_EQ(host_impl_->global_tile_state().hard_memory_limit_in_bytes,
             300u * 1024u * 1024u);
   EXPECT_EQ(host_impl_->global_tile_state().soft_memory_limit_in_bytes,
             150u * 1024u * 1024u);
   EXPECT_EQ(host_impl_->global_tile_state().unused_memory_limit_in_bytes,
             75u * 1024u * 1024u);
 }
 
 }  // namespace
 }  // namespace cc