[Android]Optimization of scrollbar animation.

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 1341 matching lines @@
 
   // If no scroll happened during a scroll gesture, it should have no effect.
   host_impl_->ScrollBegin(gfx::Point(), InputHandler::Wheel);
   host_impl_->ScrollEnd();
   EXPECT_EQ(base::TimeDelta(), requested_scrollbar_animation_delay_);
   EXPECT_FALSE(did_request_redraw_);
   EXPECT_TRUE(scrollbar_fade_start_.Equals(base::Closure()));
 
   // After a scroll, a fade animation should be scheduled about 20ms from now.
   host_impl_->ScrollBegin(gfx::Point(), InputHandler::Wheel);
-  host_impl_->ScrollBy(gfx::Point(), gfx::Vector2dF(5, 0));
+  host_impl_->ScrollBy(gfx::Point(), gfx::Vector2dF(0, 5));
   host_impl_->ScrollEnd();
   did_request_redraw_ = false;
   did_request_animate_ = false;
   EXPECT_LT(base::TimeDelta::FromMilliseconds(19),
             requested_scrollbar_animation_delay_);
   EXPECT_FALSE(did_request_redraw_);
   EXPECT_FALSE(did_request_animate_);
   requested_scrollbar_animation_delay_ = base::TimeDelta();
   scrollbar_fade_start_.Run();
   host_impl_->Animate(fake_now);
 
   // After the fade begins, we should start getting redraws instead of a
   // scheduled animation.
   fake_now += base::TimeDelta::FromMilliseconds(25);
   EXPECT_EQ(base::TimeDelta(), requested_scrollbar_animation_delay_);
   EXPECT_TRUE(did_request_animate_);
   did_request_animate_ = false;
 
   // Setting the scroll offset outside a scroll should also cause the scrollbar
   // to appear and to schedule a fade.
   host_impl_->InnerViewportScrollLayer()->SetScrollOffset(gfx::Vector2d(5, 5));
   EXPECT_LT(base::TimeDelta::FromMilliseconds(19),
             requested_scrollbar_animation_delay_);
   EXPECT_FALSE(did_request_redraw_);
   EXPECT_FALSE(did_request_animate_);
   requested_scrollbar_animation_delay_ = base::TimeDelta();
+
+  // Unnecessarily Fade animation of solid color scrollbar is not triggered.
+  host_impl_->ScrollBegin(gfx::Point(), InputHandler::Wheel);
+  host_impl_->ScrollBy(gfx::Point(), gfx::Vector2dF(5, 0));
+  host_impl_->ScrollEnd();
+  EXPECT_EQ(base::TimeDelta(), requested_scrollbar_animation_delay_);
 }
 
 TEST_F(LayerTreeHostImplTest, ScrollbarFadePinchZoomScrollbars) {
   LayerTreeSettings settings;
   settings.scrollbar_animator = LayerTreeSettings::LinearFade;
   settings.scrollbar_fade_delay_ms = 20;
   settings.scrollbar_fade_duration_ms = 20;
   settings.use_pinch_zoom_scrollbars = true;
 
   SETUP_LAYERS_FOR_SCROLLBAR_ANIMATION_TEST();
@@ skipping 5713 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