[android] Remove unused scroll delta in TopControls

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 <algorithm>
 #include <cmath>
 
 #include "base/bind.h"
@@ skipping 2574 matching lines @@
 
   gfx::ScrollOffset viewport_offset =
       host_impl_->active_tree()->TotalScrollOffset();
   EXPECT_EQ(host_impl_->active_tree()->TotalMaxScrollOffset(), viewport_offset);
 
   // Hide the top controls by 25px.
   gfx::Vector2dF scroll_delta(0.f, 25.f);
   EXPECT_EQ(InputHandler::ScrollStarted,
             host_impl_->ScrollBegin(gfx::Point(), InputHandler::Gesture));
   host_impl_->ScrollBy(gfx::Point(), scroll_delta);
+
+  // scrolling down at the max extents no longer hides the top controls
+  EXPECT_EQ(0.f,
+            settings_.top_controls_height -
+                host_impl_->active_tree()->total_top_controls_content_offset());
+
+  // forcefully hide the top controls by 25px
+  host_impl_->top_controls_manager()->ScrollBy(scroll_delta);
   host_impl_->ScrollEnd();
 
   EXPECT_EQ(scroll_delta.y(),
             settings_.top_controls_height -
                 host_impl_->active_tree()->total_top_controls_content_offset());
 
   inner_scroll->ClampScrollToMaxScrollOffset();
   outer_scroll->ClampScrollToMaxScrollOffset();
 
   // We should still be fully scrolled.
@@ skipping 4689 matching lines @@
         host_impl_->top_controls_manager()->ControlsTopOffset();
 
     if (new_offset != old_offset) {
       EXPECT_TRUE(did_request_redraw_);
       EXPECT_TRUE(did_request_commit_);
     }
   }
   EXPECT_FALSE(host_impl_->top_controls_manager()->animation());
 }
 
+TEST_F(LayerTreeHostImplWithTopControlsTest,
+       TopControlsScrollDeltaInOverScroll) {
+  // test varifies that the overscroll delta should not have accumulated in
+  // the top controls if we do a hide and show without releasing finger.
+
+  LayerImpl* scroll_layer = SetupScrollAndContentsLayers(gfx::Size(100, 200));
+  host_impl_->SetViewportSize(gfx::Size(100, 100));
+  host_impl_->top_controls_manager()->UpdateTopControlsState(BOTH, SHOWN,
+                                                             false);
+  DrawFrame();
+
+  EXPECT_EQ(InputHandler::ScrollStarted,
+            host_impl_->ScrollBegin(gfx::Point(), InputHandler::Gesture));
+  EXPECT_EQ(0, host_impl_->top_controls_manager()->ControlsTopOffset());
+
+  float offset = 50;
+  EXPECT_TRUE(
+      host_impl_->ScrollBy(gfx::Point(), gfx::Vector2d(0, offset)).did_scroll);
+  EXPECT_EQ(-offset, host_impl_->top_controls_manager()->ControlsTopOffset());
+  EXPECT_EQ(gfx::Vector2dF().ToString(),
+            scroll_layer->TotalScrollOffset().ToString());
+
+  EXPECT_TRUE(
+      host_impl_->ScrollBy(gfx::Point(), gfx::Vector2d(0, offset)).did_scroll);
+  EXPECT_EQ(gfx::Vector2dF(0, offset).ToString(),
+            scroll_layer->TotalScrollOffset().ToString());
+
+  EXPECT_TRUE(
+      host_impl_->ScrollBy(gfx::Point(), gfx::Vector2d(0, offset)).did_scroll);
+
+  // Should have fully scrolled
+  EXPECT_EQ(gfx::Vector2dF(0, scroll_layer->MaxScrollOffset().y()).ToString(),
+            scroll_layer->TotalScrollOffset().ToString());
+
+  float overscrollamount = 10;
+
+  // Overscroll the content
+  EXPECT_FALSE(
+      host_impl_->ScrollBy(gfx::Point(), gfx::Vector2d(0, overscrollamount))
+          .did_scroll);
+  EXPECT_EQ(gfx::Vector2dF(0, 2 * offset).ToString(),
+            scroll_layer->TotalScrollOffset().ToString());
+  EXPECT_EQ(gfx::Vector2dF(0, overscrollamount).ToString(),
+            host_impl_->accumulated_root_overscroll().ToString());
+
+  EXPECT_TRUE(host_impl_->ScrollBy(gfx::Point(), gfx::Vector2d(0, -2 * offset))
+                  .did_scroll);
+  EXPECT_EQ(gfx::Vector2dF(0, 0).ToString(),
+            scroll_layer->TotalScrollOffset().ToString());
+  EXPECT_EQ(-offset, host_impl_->top_controls_manager()->ControlsTopOffset());
+
+  EXPECT_TRUE(
+      host_impl_->ScrollBy(gfx::Point(), gfx::Vector2d(0, -offset)).did_scroll);
+  EXPECT_EQ(gfx::Vector2dF(0, 0).ToString(),
+            scroll_layer->TotalScrollOffset().ToString());
+
+  // Top controls should be fully visible
+  EXPECT_EQ(0, host_impl_->top_controls_manager()->ControlsTopOffset());
+
+  host_impl_->ScrollEnd();
+}
+
 class LayerTreeHostImplVirtualViewportTest : public LayerTreeHostImplTest {
  public:
   void SetupVirtualViewportLayers(const gfx::Size& content_size,
                                   const gfx::Size& outer_viewport,
                                   const gfx::Size& inner_viewport) {
     LayerTreeImpl* layer_tree_impl = host_impl_->active_tree();
     const int kOuterViewportClipLayerId = 6;
     const int kOuterViewportScrollLayerId = 7;
     const int kInnerViewportScrollLayerId = 2;
     const int kInnerViewportClipLayerId = 4;
@@ skipping 320 matching lines @@
   // surface.
   EXPECT_EQ(0, num_lost_surfaces_);
   host_impl_->DidLoseOutputSurface();
   EXPECT_EQ(1, num_lost_surfaces_);
   host_impl_->DidLoseOutputSurface();
   EXPECT_LE(1, num_lost_surfaces_);
 }
 
 }  // namespace
 }  // namespace cc