Make aborted commits inform the scroll delegate.

cc/layers/layer_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/layers/layer_impl.h"
 
 #include "cc/layers/painted_scrollbar_layer_impl.h"
 #include "cc/output/filter_operation.h"
 #include "cc/output/filter_operations.h"
 #include "cc/test/fake_impl_proxy.h"
@@ skipping 479 matching lines @@
   EXPECT_VECTOR_EQ(gfx::Vector2dF(50, 0), layer()->TotalScrollOffset());
 
   EXPECT_VECTOR_EQ(gfx::ScrollOffsetWithDelta(scroll_offset,
                                               layer()->ScrollDelta()),
                    layer()->TotalScrollOffset());
   EXPECT_VECTOR_EQ(scroll_offset, layer()->scroll_offset());
 }
 
 class ScrollDelegateIgnore : public LayerImpl::ScrollOffsetDelegate {
  public:
-  void SetTotalScrollOffset(const gfx::ScrollOffset& new_value) override {}
+  void SetTotalScrollOffset(const gfx::ScrollOffset& new_value) override {
+    last_attempted_set_offset_ = new_value;
+  }
+  gfx::ScrollOffset last_attempted_set_offset() const {
+    return last_attempted_set_offset_;
+  }
+
   gfx::ScrollOffset GetTotalScrollOffset() override {
     return gfx::ScrollOffset(fixed_offset_);
   }
   bool IsExternalFlingActive() const override { return false; }
   void Update() const override { }
 
   void set_fixed_offset(const gfx::Vector2dF& fixed_offset) {
     fixed_offset_ = fixed_offset;
   }
 
  private:
+  gfx::ScrollOffset last_attempted_set_offset_;
   gfx::Vector2dF fixed_offset_;
 };
 
 TEST_F(LayerImplScrollTest, ScrollByWithIgnoringDelegate) {
   gfx::ScrollOffset scroll_offset(10, 5);
   layer()->SetScrollOffset(scroll_offset);
 
   EXPECT_VECTOR_EQ(scroll_offset, layer()->TotalScrollOffset());
   EXPECT_VECTOR_EQ(scroll_offset, layer()->scroll_offset());
   EXPECT_VECTOR_EQ(gfx::Vector2dF(), layer()->ScrollDelta());
@@ skipping 103 matching lines @@
   delegate.set_fixed_offset(fixed_offset);
   layer()->SetScrollOffsetDelegate(&delegate);
   layer()->SetSentScrollDelta(sent_scroll_delta);
 
   EXPECT_VECTOR_EQ(fixed_offset, layer()->TotalScrollOffset());
   EXPECT_VECTOR_EQ(scroll_offset, layer()->scroll_offset());
   EXPECT_VECTOR_EQ(sent_scroll_delta, layer()->sent_scroll_delta());
 
   layer()->ApplySentScrollDeltasFromAbortedCommit();
 
+  EXPECT_VECTOR_EQ(fixed_offset, delegate.last_attempted_set_offset());
+
   EXPECT_VECTOR_EQ(fixed_offset, layer()->TotalScrollOffset());
   EXPECT_VECTOR_EQ(gfx::ScrollOffsetWithDelta(scroll_offset, sent_scroll_delta),
                    layer()->scroll_offset());
   EXPECT_VECTOR_EQ(gfx::Vector2d(), layer()->sent_scroll_delta());
 }
 
 TEST_F(LayerImplScrollTest, ApplySentScrollsWithAcceptingDelegate) {
   gfx::ScrollOffset scroll_offset(10, 5);
   gfx::Vector2d sent_scroll_delta(12, -3);
   gfx::Vector2dF scroll_delta(20.5f, 8.5f);
@@ skipping 50 matching lines @@
       layer()->id(), tree()->root_layer()->id());
 
   int expected_horizontal_maximum =
       layer()->bounds().width() - tree()->root_layer()->bounds().width();
   EXPECT_EQ(expected_horizontal_maximum, horizontal_scrollbar->maximum());
   EXPECT_EQ(scroll_offset.x(), horizontal_scrollbar->current_pos());
 }
 
 }  // namespace
 }  // namespace cc