webview: Remove LayerScrollOffsetDelegate::GetTotalScrollOffset.

This method is only called in one place, immediately after calling
UpdateRootLayerState, which sets the total scroll offset to the one
given. So cc can just re-use the offset it handed off directly instead
of setting it then getting it.

R=boliu, jdduke
BUG=531746
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel

Review URL: https://codereview.chromium.org/1341973002

Cr-Commit-Position: refs/heads/master@{#348926}

2 files changed, 6 insertions, 16 deletions

diff --git a/content/browser/android/in_process/synchronous_compositor_impl.cc b/content/browser/android/in_process/synchronous_compositor_impl.cc
index c59b2899..06d622c 100644
--- a/content/browser/android/in_process/synchronous_compositor_impl.cc
+++ b/content/browser/android/in_process/synchronous_compositor_impl.cc
@@ -273,11 +273,12 @@ void SynchronousCompositorImpl::PostInvalidate() {
     compositor_client_->PostInvalidate();
 }
 
-void SynchronousCompositorImpl::DidChangeRootLayerScrollOffset() {
+void SynchronousCompositorImpl::DidChangeRootLayerScrollOffset(
+    const gfx::ScrollOffset& root_offset) {
+  DCHECK(CalledOnValidThread());
   if (!input_handler_)
     return;
-  gfx::ScrollOffset offset = GetTotalScrollOffset();
-  input_handler_->OnRootLayerDelegatedScrollOffsetChanged(offset);
+  input_handler_->OnRootLayerDelegatedScrollOffsetChanged(root_offset);
 }
 
 void SynchronousCompositorImpl::SetIsActive(bool is_active) {
@@ -371,17 +372,6 @@ void SynchronousCompositorImpl::SetNeedsSynchronousAnimateInput() {
   compositor_client_->PostInvalidate();
 }
 
-gfx::ScrollOffset SynchronousCompositorImpl::GetTotalScrollOffset() {
-  DCHECK(CalledOnValidThread());
-  DCHECK(compositor_client_);
-  if (!registered_with_client_)
-    return gfx::ScrollOffset();
-  // TODO(miletus): Make GetTotalRootLayerScrollOffset return
-  // ScrollOffset. crbug.com/414283.
-  return gfx::ScrollOffset(
-      compositor_client_->GetTotalRootLayerScrollOffset());
-}
-
 void SynchronousCompositorImpl::UpdateRootLayerState(
     const gfx::ScrollOffset& total_scroll_offset,
     const gfx::ScrollOffset& max_scroll_offset,
diff --git a/content/browser/android/in_process/synchronous_compositor_impl.h b/content/browser/android/in_process/synchronous_compositor_impl.h
index 999ae11..2f310bd 100644
--- a/content/browser/android/in_process/synchronous_compositor_impl.h
+++ b/content/browser/android/in_process/synchronous_compositor_impl.h
@@ -79,7 +79,8 @@ class SynchronousCompositorImpl
   bool DemandDrawSw(SkCanvas* canvas) override;
   void ReturnResources(const cc::CompositorFrameAck& frame_ack) override;
   void SetMemoryPolicy(size_t bytes_limit) override;
-  void DidChangeRootLayerScrollOffset() override;
+  void DidChangeRootLayerScrollOffset(
+      const gfx::ScrollOffset& root_offset) override;
   void SetIsActive(bool is_active) override;
   void OnComputeScroll(base::TimeTicks animation_time) override;
 
@@ -87,7 +88,6 @@ class SynchronousCompositorImpl
   void SetNeedsSynchronousAnimateInput() override;
 
   // LayerScrollOffsetDelegate
-  gfx::ScrollOffset GetTotalScrollOffset() override;
   void UpdateRootLayerState(const gfx::ScrollOffset& total_scroll_offset,
                             const gfx::ScrollOffset& max_scroll_offset,
                             const gfx::SizeF& scrollable_size,