Added experiment for changing viewport scroll ordering.

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 1114 matching lines @@
     host_impl_->ScrollBy(gfx::Point(), scroll_delta);
     host_impl_->ScrollEnd();
 
     scoped_ptr<ScrollAndScaleSet> scroll_info =
         host_impl_->ProcessScrollDeltas();
     ExpectContains(*scroll_info.get(), scroll_layer->id(),
                    gfx::Vector2d(0, scroll_delta.y() / page_scale_delta));
   }
 }
 
+TEST_F(LayerTreeHostImplTest, ScrollDuringPinchScrollsInnerViewport) {
+  LayerTreeSettings settings = DefaultSettings();
+  settings.invert_viewport_scroll_order = true;
+  CreateHostImpl(settings,
+                 CreateOutputSurface());
+
+  LayerImpl* inner_scroll_layer =
+      SetupScrollAndContentsLayers(gfx::Size(100, 100));
+
+  // Adjust the content layer to be larger than the outer viewport container so
+  // that we get scrolling in both viewports.
+  LayerImpl* content_layer =
+      host_impl_->OuterViewportScrollLayer()->children().back();
+  LayerImpl* outer_scroll_layer = host_impl_->OuterViewportScrollLayer();
+  LayerImpl* inner_clip_layer =
+      host_impl_->InnerViewportScrollLayer()->parent()->parent();
+  inner_clip_layer->SetBounds(gfx::Size(100, 100));
+  inner_clip_layer->SetContentBounds(gfx::Size(100, 100));
+  outer_scroll_layer->SetBounds(gfx::Size(200, 200));
+  outer_scroll_layer->SetContentBounds(gfx::Size(200, 200));
+  content_layer->SetBounds(gfx::Size(200, 200));
+  content_layer->SetContentBounds(gfx::Size(200, 200));
+
+  host_impl_->SetViewportSize(gfx::Size(100, 100));
+
+  EXPECT_VECTOR_EQ(
+      gfx::Vector2dF(100, 100),
+      outer_scroll_layer->MaxScrollOffset());
+
+  host_impl_->ScrollBegin(gfx::Point(99, 99), InputHandler::GESTURE);
+  host_impl_->PinchGestureBegin();
+  host_impl_->PinchGestureUpdate(2, gfx::Point(99, 99));
+  host_impl_->ScrollBy(gfx::Point(99, 99), gfx::Vector2dF(10.f, 10.f));
+  host_impl_->PinchGestureEnd();
+  host_impl_->ScrollEnd();
+
+  EXPECT_VECTOR_EQ(
+      gfx::Vector2dF(0, 0),
+      outer_scroll_layer->CurrentScrollOffset());
+  EXPECT_VECTOR_EQ(
+      gfx::Vector2dF(50, 50),
+      inner_scroll_layer->CurrentScrollOffset());
+}
+
 TEST_F(LayerTreeHostImplTest, ImplPinchZoomWheelBubbleBetweenViewports) {
   LayerImpl* inner_scroll_layer =
       SetupScrollAndContentsLayers(gfx::Size(100, 100));
 
   // Adjust the content layer to be larger than the outer viewport container so
   // that we get scrolling in both viewports.
   LayerImpl* content_layer =
       host_impl_->OuterViewportScrollLayer()->children().back();
   LayerImpl* outer_scroll_layer = host_impl_->OuterViewportScrollLayer();
   LayerImpl* inner_clip_layer =
@@ skipping 6763 matching lines @@
   // Hold an unowned pointer to the output surface to use for mock expectations.
   MockReclaimResourcesOutputSurface* mock_output_surface = output_surface.get();
 
   CreateHostImpl(DefaultSettings(), output_surface.Pass());
   EXPECT_CALL(*mock_output_surface, ForceReclaimResources()).Times(1);
   host_impl_->BeginCommit();
 }
 
 }  // namespace
 }  // namespace cc