[android] Remove unused scroll delta in TopControls

cc/trees/layer_tree_host_impl_unittest.cc

Index: cc/trees/layer_tree_host_impl_unittest.cc
diff --git a/cc/trees/layer_tree_host_impl_unittest.cc b/cc/trees/layer_tree_host_impl_unittest.cc
index 5694c01aaa37565bec2f4254a0a41db9cb8092da..5d97fc29656ec39558b122843ece2c8e5af32751 100644
--- a/cc/trees/layer_tree_host_impl_unittest.cc
+++ b/cc/trees/layer_tree_host_impl_unittest.cc
@@ -2579,14 +2579,15 @@ TEST_F(LayerTreeHostImplTopControlsTest, TopControlsViewportOffsetClamping) {
       host_impl_->active_tree()->TotalScrollOffset();
   EXPECT_EQ(host_impl_->active_tree()->TotalMaxScrollOffset(), viewport_offset);
 
-  // Hide the top controls by 25px.
+  // Try to 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);
   host_impl_->ScrollEnd();
 
-  EXPECT_EQ(scroll_delta.y(),
+  // top controls should not hide, since we reached max scrolloffset
+  EXPECT_EQ(0.f,

[bokan, 2014/11/06 16:14:57]

This is fine, since scrolling down at the max extents no longer hides the top
controls; however, after this check we should still hide the top controls so the
rest of the test remains relevant. I would do that either by scrolling the top
controls directly (host_impl_->TopControlsManager()->ScrollBy()) or using the
TopControlsManager::UpdateTopControlsState method. Then perhaps do a sanity
check (as before) that the top controls are actually hidden. 

[sujith, 2014/11/07 05:06:40]

Done.

             settings_.top_controls_height -
                 host_impl_->active_tree()->total_top_controls_content_offset());
 
@@ -2606,8 +2607,8 @@ TEST_F(LayerTreeHostImplTopControlsTest, TopControlsViewportOffsetClamping) {
   host_impl_->ScrollBy(gfx::Point(), scroll_delta);
   host_impl_->ScrollEnd();
 
-  // The viewport offset shouldn't have changed.
-  EXPECT_EQ(viewport_offset,
+  // The viewport offset should have changed only by the negative offset.
+  EXPECT_EQ(viewport_offset + gfx::ScrollOffset(0.f, -25.f),

[sujith, 2014/11/06 09:28:00]

Since the +ve scroll will not reflect, if we scroll again with the -ve
value then the viewport_offset value also need to be updated. So i have 
modified the viewport_offset with the -ve scroll Offset.

[bokan, 2014/11/06 16:14:57]

If you hide the top controls as mentioned in my comment above, you should no
longer need to change this.

[sujith, 2014/11/07 05:06:40]

Done.

             host_impl_->active_tree()->TotalScrollOffset());
 
   // Scroll the viewports to max scroll offset.
@@ -7198,6 +7199,63 @@ TEST_F(LayerTreeHostImplWithTopControlsTest, TopControlsAnimationAfterScroll) {
   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)));
+  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)));
+  EXPECT_EQ(gfx::Vector2dF(0, offset).ToString(),
+            scroll_layer->TotalScrollOffset().ToString());
+
+  EXPECT_TRUE(host_impl_->ScrollBy(gfx::Point(), gfx::Vector2d(0, offset)));
+
+  // 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)));
+  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)));
+  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)));
+  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,