Remove touch scroll chaining from compositor scrolling.

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 1035 matching lines @@
 
   overflow->set_user_scrollable_horizontal(false);
 
   EXPECT_EQ(InputHandler::SCROLL_STARTED,
             host_impl_->ScrollBegin(scroll_position, InputHandler::WHEEL));
   EXPECT_VECTOR_EQ(gfx::Vector2dF(), scroll_layer->CurrentScrollOffset());
   EXPECT_VECTOR_EQ(gfx::Vector2dF(10, 10), overflow->CurrentScrollOffset());
 
   host_impl_->ScrollBy(scroll_position, scroll_delta);
   host_impl_->ScrollEnd();
-  EXPECT_VECTOR_EQ(gfx::Vector2dF(10, 0), scroll_layer->CurrentScrollOffset());
+  EXPECT_VECTOR_EQ(gfx::Vector2dF(0, 0), scroll_layer->CurrentScrollOffset());
   EXPECT_VECTOR_EQ(gfx::Vector2dF(10, 20), overflow->CurrentScrollOffset());
 
   overflow->set_user_scrollable_vertical(false);
 
   EXPECT_EQ(InputHandler::SCROLL_STARTED,
             host_impl_->ScrollBegin(scroll_position, InputHandler::WHEEL));
-  EXPECT_VECTOR_EQ(gfx::Vector2dF(10, 0), scroll_layer->CurrentScrollOffset());
+  EXPECT_VECTOR_EQ(gfx::Vector2dF(0, 0), scroll_layer->CurrentScrollOffset());
   EXPECT_VECTOR_EQ(gfx::Vector2dF(10, 20), overflow->CurrentScrollOffset());
 
   host_impl_->ScrollBy(scroll_position, scroll_delta);
   host_impl_->ScrollEnd();
-  EXPECT_VECTOR_EQ(gfx::Vector2dF(20, 10), scroll_layer->CurrentScrollOffset());
+  EXPECT_VECTOR_EQ(gfx::Vector2dF(10, 10), scroll_layer->CurrentScrollOffset());
   EXPECT_VECTOR_EQ(gfx::Vector2dF(10, 20), overflow->CurrentScrollOffset());
 }
 
 TEST_F(LayerTreeHostImplTest, AnimationSchedulingPendingTree) {
   host_impl_->SetViewportSize(gfx::Size(50, 50));
 
   host_impl_->CreatePendingTree();
   host_impl_->pending_tree()->SetRootLayer(
       LayerImpl::Create(host_impl_->pending_tree(), 1));
   LayerImpl* root = host_impl_->pending_tree()->root_layer();
@@ skipping 422 matching lines @@
             host_impl_->ScrollBegin(gfx::Point(), InputHandler::GESTURE));
   host_impl_->ScrollBy(gfx::Point(), gfx::Vector2d(0, 10));
   host_impl_->QueueSwapPromiseForMainThreadScrollUpdate(swap_promise.Pass());
   host_impl_->ScrollEnd();
 
   scoped_ptr<ScrollAndScaleSet> scroll_info = host_impl_->ProcessScrollDeltas();
   EXPECT_EQ(1u, scroll_info->swap_promises.size());
   EXPECT_EQ(latency_info.trace_id(), scroll_info->swap_promises[0]->TraceId());
 }
 
-// Test that scrolls targeting a layer with a non-null scroll_parent() bubble
-// up to the scroll_parent, rather than the stacking parent.
-TEST_F(LayerTreeHostImplTest, ScrollBubblesToScrollParent) {
+// Test that scrolls targeting a layer with a non-null scroll_parent() don't
+// bubble up.
+TEST_F(LayerTreeHostImplTest, ScrollDoesntBubble) {
   LayerImpl* viewport_scroll =
       SetupScrollAndContentsLayers(gfx::Size(100, 100));
   host_impl_->SetViewportSize(gfx::Size(50, 50));
 
   // Set up two scrolling children of the root, one of which is a scroll parent
-  // to the other. Scrolls bubbling from the child should bubble to the parent,
-  // not the viewport.
+  // to the other. Scrolls shouldn't bubbling from the child.
   LayerImpl *parent;
   LayerImpl *child;
   LayerImpl *child_clip;
 
   scoped_ptr<LayerImpl> scroll_parent_clip =
       LayerImpl::Create(host_impl_->active_tree(), 6);
   scoped_ptr<LayerImpl> scroll_parent = CreateScrollableLayer(
       7, gfx::Size(10, 10), scroll_parent_clip.get());
   parent = scroll_parent.get();
   scroll_parent_clip->AddChild(scroll_parent.Pass());
@@ skipping 11 matching lines @@
   child_clip = scroll_child_clip.get();
   viewport_scroll->AddChild(scroll_child_clip.Pass());
 
   child_clip->SetScrollParent(parent);
 
   DrawFrame();
 
   {
     host_impl_->ScrollBegin(gfx::Point(21, 21), InputHandler::GESTURE);
     host_impl_->ScrollBy(gfx::Point(21, 21), gfx::Vector2d(5, 5));
-    host_impl_->ScrollBy(gfx::Point(21, 21), gfx::Vector2d(2, 1));
+    host_impl_->ScrollBy(gfx::Point(21, 21), gfx::Vector2d(100, 100));
     host_impl_->ScrollEnd();
 
     // The child should be fully scrolled by the first ScrollBy.
     EXPECT_VECTOR_EQ(gfx::Vector2dF(5, 5), child->CurrentScrollOffset());
 
-    // The scroll_parent should receive the bubbled up second ScrollBy.
-    EXPECT_VECTOR_EQ(gfx::Vector2dF(2, 1), parent->CurrentScrollOffset());
+    // The scroll_parent shouldn't receive the second ScrollBy.
+    EXPECT_VECTOR_EQ(gfx::Vector2dF(0, 0), parent->CurrentScrollOffset());
 
     // The viewport shouldn't have been scrolled at all.
     EXPECT_VECTOR_EQ(
         gfx::Vector2dF(0, 0),
         host_impl_->InnerViewportScrollLayer()->CurrentScrollOffset());
     EXPECT_VECTOR_EQ(
         gfx::Vector2dF(0, 0),
         host_impl_->OuterViewportScrollLayer()->CurrentScrollOffset());
   }
 
   {
     host_impl_->ScrollBegin(gfx::Point(21, 21), InputHandler::GESTURE);
     host_impl_->ScrollBy(gfx::Point(21, 21), gfx::Vector2d(3, 4));
     host_impl_->ScrollBy(gfx::Point(21, 21), gfx::Vector2d(2, 1));
+    host_impl_->ScrollBy(gfx::Point(21, 21), gfx::Vector2d(2, 1));
+    host_impl_->ScrollBy(gfx::Point(21, 21), gfx::Vector2d(2, 1));
     host_impl_->ScrollEnd();
 
-    // The first ScrollBy should scroll the parent to its extent.
+    // The ScrollBy's should scroll the parent to its extent.
     EXPECT_VECTOR_EQ(gfx::Vector2dF(5, 5), parent->CurrentScrollOffset());
 
-    // The viewport should now be next in bubbling order.
+    // The viewport shouldn't receive any scroll delta.
     EXPECT_VECTOR_EQ(
-        gfx::Vector2dF(2, 1),
+        gfx::Vector2dF(0, 0),
         host_impl_->InnerViewportScrollLayer()->CurrentScrollOffset());
     EXPECT_VECTOR_EQ(
         gfx::Vector2dF(0, 0),
         host_impl_->OuterViewportScrollLayer()->CurrentScrollOffset());
   }
 }
 
 
 TEST_F(LayerTreeHostImplTest, PinchGesture) {
   SetupScrollAndContentsLayers(gfx::Size(100, 100));
@@ skipping 2007 matching lines @@
 
   EXPECT_EQ(top_controls_height_,
             host_impl_->top_controls_manager()->ContentTopOffset());
 
   // Send a gesture scroll that will scroll the outer viewport, make sure the
   // top controls get scrolled.
   gfx::Vector2dF scroll_delta(0.f, 15.f);
   EXPECT_EQ(InputHandler::SCROLL_STARTED,
             host_impl_->ScrollBegin(gfx::Point(), InputHandler::GESTURE));
   host_impl_->ScrollBy(gfx::Point(), scroll_delta);
-  EXPECT_EQ(host_impl_->OuterViewportScrollLayer(),
+
+  EXPECT_EQ(host_impl_->InnerViewportScrollLayer(),
             host_impl_->CurrentlyScrollingLayer());
   host_impl_->ScrollEnd();
 
   EXPECT_FLOAT_EQ(scroll_delta.y(),
                   top_controls_height_ -
                       host_impl_->top_controls_manager()->ContentTopOffset());
 
   scroll_delta = gfx::Vector2dF(0.f, 50.f);
   EXPECT_EQ(InputHandler::SCROLL_STARTED,
             host_impl_->ScrollBegin(gfx::Point(), InputHandler::GESTURE));
   host_impl_->ScrollBy(gfx::Point(), scroll_delta);
 
   EXPECT_EQ(0, host_impl_->top_controls_manager()->ContentTopOffset());
-  EXPECT_EQ(host_impl_->OuterViewportScrollLayer(),
+  EXPECT_EQ(host_impl_->InnerViewportScrollLayer(),
             host_impl_->CurrentlyScrollingLayer());
 
   host_impl_->ScrollEnd();
 
   // Position the viewports such that the inner viewport will be scrolled.
   gfx::Vector2dF inner_viewport_offset(0.f, 25.f);
   host_impl_->OuterViewportScrollLayer()->SetScrollDelta(gfx::Vector2dF());
   host_impl_->InnerViewportScrollLayer()->SetScrollDelta(inner_viewport_offset);
 
   scroll_delta = gfx::Vector2dF(0.f, -65.f);
@@ skipping 359 matching lines @@
   // The scroll range should not have changed.
   EXPECT_EQ(outer_scroll->MaxScrollOffset(), expected_max_scroll);
 
   // The page scale delta remains constant because the impl thread did not
   // scale.
   EXPECT_EQ(1.f, host_impl_->active_tree()->page_scale_delta());
 }
 
 TEST_F(LayerTreeHostImplTest, ScrollChildBeyondLimit) {
   // Scroll a child layer beyond its maximum scroll range and make sure the
-  // parent layer is scrolled on the axis on which the child was unable to
-  // scroll.
+  // parent layer isn't scrolled.
   gfx::Size surface_size(10, 10);
   gfx::Size content_size(20, 20);
   scoped_ptr<LayerImpl> root = LayerImpl::Create(host_impl_->active_tree(), 1);
   root->SetBounds(surface_size);
   root->SetHasRenderSurface(true);
   scoped_ptr<LayerImpl> grand_child =
       CreateScrollableLayer(3, content_size, root.get());
 
   scoped_ptr<LayerImpl> child =
       CreateScrollableLayer(2, content_size, root.get());
@@ skipping 18 matching lines @@
 
     scoped_ptr<ScrollAndScaleSet> scroll_info =
         host_impl_->ProcessScrollDeltas();
 
     // The grand child should have scrolled up to its limit.
     LayerImpl* child = host_impl_->active_tree()->root_layer()->children()[0];
     LayerImpl* grand_child = child->children()[0];
     EXPECT_TRUE(ScrollInfoContains(*scroll_info.get(), grand_child->id(),
                                    gfx::Vector2d(0, -5)));
 
-    // The child should have only scrolled on the other axis.
-    EXPECT_TRUE(ScrollInfoContains(*scroll_info.get(), child->id(),
-                                   gfx::Vector2d(-3, 0)));
+    // The child should not have scrolled.
+    ExpectNone(*scroll_info.get(), child->id());
   }
 }
 
 TEST_F(LayerTreeHostImplTest, ScrollWithoutBubbling) {
   // Scroll a child layer beyond its maximum scroll range and make sure the
   // the scroll doesn't bubble up to the parent layer.
   gfx::Size surface_size(20, 20);
   gfx::Size viewport_size(10, 10);
   scoped_ptr<LayerImpl> root = LayerImpl::Create(host_impl_->active_tree(), 1);
   root->SetHasRenderSurface(true);
@@ skipping 278 matching lines @@
   }
   {
     // Now reset and scroll the same amount horizontally.
     child_ptr->SetScrollDelta(gfx::Vector2dF());
     gfx::Vector2d gesture_scroll_delta(10, 0);
     EXPECT_EQ(InputHandler::SCROLL_STARTED,
               host_impl_->ScrollBegin(gfx::Point(1, 1), InputHandler::GESTURE));
     host_impl_->ScrollBy(gfx::Point(), gesture_scroll_delta);
     host_impl_->ScrollEnd();
 
-    // The child layer should have scrolled down in its local coordinates an
-    // amount proportional to the angle between it and the input scroll delta.
+    // The child layer shouldn't have scrolled.
     gfx::Vector2d expected_scroll_delta(
         0, -gesture_scroll_delta.x() *
                std::sin(MathUtil::Deg2Rad(child_layer_angle)));
     scoped_ptr<ScrollAndScaleSet> scroll_info =
         host_impl_->ProcessScrollDeltas();
     EXPECT_TRUE(ScrollInfoContains(*scroll_info.get(), child_layer_id,
                                    expected_scroll_delta));
 
-    // The root scroll layer should have scrolled more, since the input scroll
-    // delta was mostly orthogonal to the child layer's vertical scroll axis.
-    gfx::Vector2d expected_root_scroll_delta(
-        gesture_scroll_delta.x() *
-            std::pow(std::cos(MathUtil::Deg2Rad(child_layer_angle)), 2),
-        0);
-    EXPECT_TRUE(ScrollInfoContains(*scroll_info.get(), scroll_layer->id(),
-                                   expected_root_scroll_delta));
+    // The root scroll layer shouldn't have scrolled.
+    ExpectNone(*scroll_info.get(), scroll_layer->id());
   }
 }
 
 TEST_F(LayerTreeHostImplTest, ScrollPerspectiveTransformedLayer) {
   // When scrolling an element with perspective, the distance scrolled
   // depends on the point at which the scroll begins.
   LayerImpl* scroll_layer = SetupScrollAndContentsLayers(gfx::Size(100, 100));
   int child_clip_layer_id = 6;
   int child_layer_id = 7;
 
@@ skipping 2270 matching lines @@
 
     scoped_ptr<ScrollAndScaleSet> scroll_info =
         host_impl_->ProcessScrollDeltas();
 
     // Only the child should have scrolled.
     ASSERT_EQ(1u, scroll_info->scrolls.size());
     ExpectNone(*scroll_info.get(), root_id);
   }
 }
 
-TEST_F(LayerTreeHostImplTest, TouchFlingShouldLockToFirstScrolledLayer) {
+TEST_F(LayerTreeHostImplTest, TouchFlingShouldContinueScrollingCurrentLayer) {
   // Scroll a child layer beyond its maximum scroll range and make sure the
   // the scroll doesn't bubble up to the parent layer.
   gfx::Size surface_size(10, 10);
   scoped_ptr<LayerImpl> root = LayerImpl::Create(host_impl_->active_tree(), 1);
   root->SetHasRenderSurface(true);
   scoped_ptr<LayerImpl> root_scrolling =
       CreateScrollableLayer(2, surface_size, root.get());
 
   scoped_ptr<LayerImpl> grand_child =
       CreateScrollableLayer(4, surface_size, root.get());
@@ skipping 21 matching lines @@
               host_impl_->ScrollBegin(gfx::Point(), InputHandler::GESTURE));
     EXPECT_TRUE(host_impl_->ScrollBy(gfx::Point(), scroll_delta).did_scroll);
 
     // The grand child should have scrolled up to its limit.
     scroll_info = host_impl_->ProcessScrollDeltas();
     ASSERT_EQ(1u, scroll_info->scrolls.size());
     EXPECT_TRUE(
         ScrollInfoContains(*scroll_info, grand_child->id(), scroll_delta));
     EXPECT_EQ(host_impl_->CurrentlyScrollingLayer(), grand_child);
 
-    // The child should have received the bubbled delta, but the locked
-    // scrolling layer should remain set as the grand child.
-    EXPECT_TRUE(host_impl_->ScrollBy(gfx::Point(), scroll_delta).did_scroll);
+    // The locked scrolling layer should remain set as the grand child.
+    EXPECT_FALSE(host_impl_->ScrollBy(gfx::Point(), scroll_delta).did_scroll);
     scroll_info = host_impl_->ProcessScrollDeltas();
-    ASSERT_EQ(2u, scroll_info->scrolls.size());
+    ASSERT_EQ(1u, scroll_info->scrolls.size());
     EXPECT_TRUE(
         ScrollInfoContains(*scroll_info, grand_child->id(), scroll_delta));
-    EXPECT_TRUE(ScrollInfoContains(*scroll_info, child->id(), scroll_delta));
+    ExpectNone(*scroll_info, child->id());
     EXPECT_EQ(host_impl_->CurrentlyScrollingLayer(), grand_child);
 
-    // The first |ScrollBy| after the fling should re-lock the scrolling
-    // layer to the first layer that scrolled, which is the child.
     EXPECT_EQ(InputHandler::SCROLL_STARTED, host_impl_->FlingScrollBegin());
-    EXPECT_TRUE(host_impl_->ScrollBy(gfx::Point(), scroll_delta).did_scroll);
-    EXPECT_EQ(host_impl_->CurrentlyScrollingLayer(), child);
+    EXPECT_FALSE(host_impl_->ScrollBy(gfx::Point(), scroll_delta).did_scroll);
+    EXPECT_EQ(host_impl_->CurrentlyScrollingLayer(), grand_child);
 
-    // The child should have scrolled up to its limit.
+    // The child should not have scrolled.
     scroll_info = host_impl_->ProcessScrollDeltas();
-    ASSERT_EQ(2u, scroll_info->scrolls.size());
+    ASSERT_EQ(1u, scroll_info->scrolls.size());
     EXPECT_TRUE(
         ScrollInfoContains(*scroll_info, grand_child->id(), scroll_delta));
-    EXPECT_TRUE(ScrollInfoContains(*scroll_info, child->id(),
-                                   scroll_delta + scroll_delta));
+    ExpectNone(*scroll_info, child->id());
 
     // As the locked layer is at it's limit, no further scrolling can occur.
     EXPECT_FALSE(host_impl_->ScrollBy(gfx::Point(), scroll_delta).did_scroll);
-    EXPECT_EQ(host_impl_->CurrentlyScrollingLayer(), child);
+    EXPECT_EQ(host_impl_->CurrentlyScrollingLayer(), grand_child);
     host_impl_->ScrollEnd();
   }
 }
 
-TEST_F(LayerTreeHostImplTest, WheelFlingShouldBubble) {
-  // When flinging via wheel, the root should eventually scroll (we should
-  // bubble).
+TEST_F(LayerTreeHostImplTest, WheelFlingShouldntBubble) {
+  // When flinging via wheel, we shouldn't bubble.
   gfx::Size surface_size(10, 10);
   gfx::Size content_size(20, 20);
   scoped_ptr<LayerImpl> root_clip =
       LayerImpl::Create(host_impl_->active_tree(), 3);
   root_clip->SetHasRenderSurface(true);
   scoped_ptr<LayerImpl> root_scroll =
       CreateScrollableLayer(1, content_size, root_clip.get());
   int root_scroll_id = root_scroll->id();
   scoped_ptr<LayerImpl> child =
       CreateScrollableLayer(2, content_size, root_clip.get());
@@ skipping 13 matching lines @@
 
     gfx::Vector2d scroll_delta(0, 100);
     host_impl_->ScrollBy(gfx::Point(), scroll_delta);
     host_impl_->ScrollBy(gfx::Point(), scroll_delta);
 
     host_impl_->ScrollEnd();
 
     scoped_ptr<ScrollAndScaleSet> scroll_info =
         host_impl_->ProcessScrollDeltas();
 
-    // The root should have scrolled.
-    ASSERT_EQ(2u, scroll_info->scrolls.size());
-    EXPECT_TRUE(ScrollInfoContains(*scroll_info.get(), root_scroll_id,
-                                   gfx::Vector2d(0, 10)));
+    // The root shouldn't have scrolled.
+    ASSERT_EQ(1u, scroll_info->scrolls.size());
+    ExpectNone(*scroll_info.get(), root_scroll_id);
   }
 }
 
 TEST_F(LayerTreeHostImplTest, ScrollUnknownNotOnAncestorChain) {
   // If we ray cast a scroller that is not on the first layer's ancestor chain,
   // we should return SCROLL_UNKNOWN.
   gfx::Size content_size(100, 100);
   SetupScrollAndContentsLayers(content_size);
 
   int scroll_layer_id = 2;
@@ skipping 919 matching lines @@
   DrawFrame();
   {
     gfx::Vector2dF inner_expected;
     gfx::Vector2dF outer_expected;
     EXPECT_VECTOR_EQ(inner_expected, inner_scroll->CurrentScrollOffset());
     EXPECT_VECTOR_EQ(outer_expected, outer_scroll->CurrentScrollOffset());
 
     // Make sure the fling goes to the outer viewport first
     EXPECT_EQ(InputHandler::SCROLL_STARTED,
               host_impl_->ScrollBegin(gfx::Point(), InputHandler::GESTURE));
-    EXPECT_EQ(outer_scroll, host_impl_->CurrentlyScrollingLayer());
+    EXPECT_EQ(inner_scroll, host_impl_->CurrentlyScrollingLayer());
     EXPECT_EQ(InputHandler::SCROLL_STARTED, host_impl_->FlingScrollBegin());
-    EXPECT_EQ(outer_scroll, host_impl_->CurrentlyScrollingLayer());
+    EXPECT_EQ(inner_scroll, host_impl_->CurrentlyScrollingLayer());
 
     gfx::Vector2d scroll_delta(inner_viewport.width(), inner_viewport.height());
     host_impl_->ScrollBy(gfx::Point(), scroll_delta);
     outer_expected += gfx::Vector2dF(scroll_delta.x(), scroll_delta.y());
-    EXPECT_EQ(host_impl_->CurrentlyScrollingLayer(), outer_scroll);
+    EXPECT_EQ(inner_scroll, host_impl_->CurrentlyScrollingLayer());
 
     host_impl_->ScrollEnd();
     EXPECT_EQ(nullptr, host_impl_->CurrentlyScrollingLayer());
 
     EXPECT_VECTOR_EQ(inner_expected, inner_scroll->CurrentScrollOffset());
     EXPECT_VECTOR_EQ(outer_expected, outer_scroll->CurrentScrollOffset());
 
     // Fling past the outer viewport boundry, make sure inner viewport scrolls.
     EXPECT_EQ(InputHandler::SCROLL_STARTED,
               host_impl_->ScrollBegin(gfx::Point(), InputHandler::GESTURE));
-    EXPECT_EQ(outer_scroll, host_impl_->CurrentlyScrollingLayer());
+    EXPECT_EQ(inner_scroll, host_impl_->CurrentlyScrollingLayer());
     EXPECT_EQ(InputHandler::SCROLL_STARTED, host_impl_->FlingScrollBegin());
-    EXPECT_EQ(outer_scroll, host_impl_->CurrentlyScrollingLayer());
+    EXPECT_EQ(inner_scroll, host_impl_->CurrentlyScrollingLayer());
 
     host_impl_->ScrollBy(gfx::Point(), scroll_delta);
     outer_expected += gfx::Vector2dF(scroll_delta.x(), scroll_delta.y());
-    EXPECT_EQ(outer_scroll, host_impl_->CurrentlyScrollingLayer());
+    EXPECT_EQ(inner_scroll, host_impl_->CurrentlyScrollingLayer());
 
     host_impl_->ScrollBy(gfx::Point(), scroll_delta);
     inner_expected += gfx::Vector2dF(scroll_delta.x(), scroll_delta.y());
-    EXPECT_EQ(outer_scroll, host_impl_->CurrentlyScrollingLayer());
+    EXPECT_EQ(inner_scroll, host_impl_->CurrentlyScrollingLayer());
 
     host_impl_->ScrollEnd();
     EXPECT_EQ(nullptr, host_impl_->CurrentlyScrollingLayer());
 
     EXPECT_VECTOR_EQ(inner_expected, inner_scroll->CurrentScrollOffset());
     EXPECT_VECTOR_EQ(outer_expected, outer_scroll->CurrentScrollOffset());
   }
 }
 
 TEST_F(LayerTreeHostImplVirtualViewportTest,
@@ skipping 41 matching lines @@
     host_impl_->ScrollEnd();
     EXPECT_FALSE(host_impl_->IsCurrentlyScrollingLayerAt(
         gfx::Point(), InputHandler::GESTURE));
 
     EXPECT_VECTOR_EQ(inner_expected, inner_scroll->CurrentScrollOffset());
     EXPECT_VECTOR_EQ(outer_expected, outer_scroll->CurrentScrollOffset());
   }
 }
 
 TEST_F(LayerTreeHostImplVirtualViewportTest,
-       TouchFlingCanLockToViewportLayerAfterBubbling) {
+       TouchFlingDoesntSwitchScrollingLayer) {
   gfx::Size content_size = gfx::Size(100, 160);
   gfx::Size outer_viewport = gfx::Size(50, 80);
   gfx::Size inner_viewport = gfx::Size(25, 40);
 
   SetupVirtualViewportLayers(content_size, outer_viewport, inner_viewport);
 
   LayerImpl* outer_scroll = host_impl_->OuterViewportScrollLayer();
   LayerImpl* inner_scroll = host_impl_->InnerViewportScrollLayer();
 
   scoped_ptr<LayerImpl> child =
@@ skipping 12 matching lines @@
     EXPECT_TRUE(host_impl_->IsCurrentlyScrollingLayerAt(gfx::Point(),
                                                         InputHandler::GESTURE));
 
     // The child should have scrolled up to its limit.
     scroll_info = host_impl_->ProcessScrollDeltas();
     ASSERT_EQ(1u, scroll_info->scrolls.size());
     EXPECT_TRUE(
         ScrollInfoContains(*scroll_info, child_scroll->id(), scroll_delta));
     EXPECT_EQ(host_impl_->CurrentlyScrollingLayer(), child_scroll);
 
-    // The first |ScrollBy| after the fling should re-lock the scrolling
-    // layer to the first layer that scrolled, the inner viewport scroll layer.
+    // The fling have no effect on the currently scrolling layer.
     EXPECT_EQ(InputHandler::SCROLL_STARTED, host_impl_->FlingScrollBegin());
-    EXPECT_TRUE(host_impl_->ScrollBy(gfx::Point(), scroll_delta).did_scroll);
-    EXPECT_EQ(host_impl_->CurrentlyScrollingLayer(), inner_scroll);
+    EXPECT_FALSE(host_impl_->ScrollBy(gfx::Point(), scroll_delta).did_scroll);
+    EXPECT_EQ(host_impl_->CurrentlyScrollingLayer(), child_scroll);
     EXPECT_TRUE(host_impl_->IsCurrentlyScrollingLayerAt(gfx::Point(),
                                                         InputHandler::GESTURE));
 
-    // The inner viewport should have scrolled up to its limit.
+    // The inner viewport shouldn't have scrolled.
     scroll_info = host_impl_->ProcessScrollDeltas();
-    ASSERT_EQ(2u, scroll_info->scrolls.size());
+    ASSERT_EQ(1u, scroll_info->scrolls.size());
     EXPECT_TRUE(
         ScrollInfoContains(*scroll_info, child_scroll->id(), scroll_delta));
-    EXPECT_TRUE(
-        ScrollInfoContains(*scroll_info, inner_scroll->id(), scroll_delta));
+    ExpectNone(*scroll_info, inner_scroll->id());
 
     // As the locked layer is at its limit, no further scrolling can occur.
     EXPECT_FALSE(host_impl_->ScrollBy(gfx::Point(), scroll_delta).did_scroll);
-    EXPECT_EQ(host_impl_->CurrentlyScrollingLayer(), inner_scroll);
+    EXPECT_EQ(host_impl_->CurrentlyScrollingLayer(), child_scroll);
     host_impl_->ScrollEnd();
     EXPECT_FALSE(host_impl_->IsCurrentlyScrollingLayerAt(
         gfx::Point(), InputHandler::GESTURE));
   }
 }
 
 TEST_F(LayerTreeHostImplVirtualViewportTest,
        ScrollBeginEventThatTargetsViewportLayerSkipsHitTest) {
   gfx::Size content_size = gfx::Size(100, 160);
   gfx::Size outer_viewport = gfx::Size(50, 80);
@@ skipping 648 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