Fixed position layer counter-scroll with main thread scroll offset fractional part

cc/blink/web_layer_impl.cc

 // Copyright 2014 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/blink/web_layer_impl.h"
 
 #include "base/bind.h"
 #include "base/debug/trace_event_impl.h"
 #include "base/lazy_instance.h"
 #include "base/strings/string_util.h"
@@ skipping 255 matching lines @@
 }
 
 void WebLayerImpl::setForceRenderSurface(bool force_render_surface) {
   layer_->SetForceRenderSurface(force_render_surface);
 }
 
 void WebLayerImpl::setScrollPositionDouble(blink::WebDoublePoint position) {
   layer_->SetScrollOffset(gfx::ScrollOffset(position.x, position.y));
 }
 
+void WebLayerImpl::setScrollPositionFractionalPart(
+    blink::WebDoublePoint position) {
+  layer_->SetScrollOffsetFractionalPart(gfx::Vector2dF(position.x, position.y));
+}
+
 blink::WebDoublePoint WebLayerImpl::scrollPositionDouble() const {
   return blink::WebDoublePoint(layer_->scroll_offset().x(),
                                layer_->scroll_offset().y());
 }
 
 void WebLayerImpl::setScrollClipLayer(WebLayer* clip_layer) {
   if (!clip_layer) {
     layer_->SetScrollClipLayerId(Layer::INVALID_ID);
     return;
   }
@@ skipping 187 matching lines @@
   if (parent)
     clip_parent = static_cast<WebLayerImpl*>(parent)->layer();
   layer_->SetClipParent(clip_parent);
 }
 
 Layer* WebLayerImpl::layer() const {
   return layer_.get();
 }
 
 }  // namespace cc_blink