Always fall back to root scroll layer for otherwise ignored scrolls

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 1762 matching lines @@
                                          layer_size.height()));
   root->SetBounds(layer_size);
   root->SetContentBounds(layer_size);
   root->SetPosition(gfx::PointF());
   root->SetAnchorPoint(gfx::PointF());
   root->SetDrawsContent(false);
   host_impl_->active_tree()->SetRootLayer(root.Pass());
   host_impl_->active_tree()->FindRootScrollLayer();
   DrawFrame();
 
-  EXPECT_EQ(InputHandler::ScrollIgnored,
+  EXPECT_EQ(InputHandler::ScrollStarted,
             host_impl_->ScrollBegin(gfx::Point(), InputHandler::Gesture));
 
   host_impl_->top_controls_manager()->ScrollBegin();
   host_impl_->top_controls_manager()->ScrollBy(gfx::Vector2dF(0.f, 50.f));
   host_impl_->top_controls_manager()->ScrollEnd();
   EXPECT_EQ(host_impl_->top_controls_manager()->content_top_offset(), 0.f);
 
+  host_impl_->ScrollEnd();
+
   EXPECT_EQ(InputHandler::ScrollStarted,
             host_impl_->ScrollBegin(gfx::Point(),
                                     InputHandler::Gesture));
 }
 
 TEST_F(LayerTreeHostImplTest, ScrollNonCompositedRoot) {
   // Test the configuration where a non-composited root layer is embedded in a
   // scrollable outer layer.
   gfx::Size surface_size(10, 10);
 
@@ skipping 914 matching lines @@
     host_impl_->ScrollBy(gfx::Point(), scroll_delta);
     EXPECT_EQ(gfx::Vector2dF(0, 6), host_impl_->accumulated_root_overscroll());
     host_impl_->ScrollBy(gfx::Point(), scroll_delta);
     EXPECT_EQ(gfx::Vector2dF(0, 14), host_impl_->accumulated_root_overscroll());
     host_impl_->ScrollEnd();
   }
 }
 
 TEST_F(LayerTreeHostImplTest, OverscrollAlways) {
   LayerTreeSettings settings;
-  settings.always_overscroll = true;
   CreateHostImpl(settings, CreateOutputSurface());
 
   SetupScrollAndContentsLayers(gfx::Size(50, 50));
   host_impl_->SetViewportSize(gfx::Size(50, 50));
   host_impl_->active_tree()->SetPageScaleFactorAndLimits(1.f, 0.5f, 4.f);
   DrawFrame();
   EXPECT_EQ(gfx::Vector2dF(), host_impl_->accumulated_root_overscroll());
   EXPECT_EQ(gfx::Vector2dF(), host_impl_->current_fling_velocity());
 
   // Even though the layer can't scroll the overscroll still happens.
@@ skipping 2695 matching lines @@
                                      &set_needs_redraw_count));
     // Empty damage rect won't signal the monitor.
     host_impl_->SetNeedsRedrawRect(gfx::Rect());
     EXPECT_EQ(0, set_needs_commit_count);
     EXPECT_EQ(2, set_needs_redraw_count);
   }
 }
 
 }  // namespace
 }  // namespace cc