Always fall back to root scroll layer for otherwise ignored scrolls

content/renderer/gpu/render_widget_compositor.cc

 // Copyright (c) 2013 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 "content/renderer/gpu/render_widget_compositor.h"
 
 #include <limits>
 #include <string>
 
 #if defined(OS_ANDROID)
@@ skipping 246 matching lines @@
   settings.max_partial_texture_updates = 0;
   settings.scrollbar_animator = cc::LayerTreeSettings::LinearFade;
   settings.solid_color_scrollbar_color =
       cmd->HasSwitch(switches::kHideScrollbars)
           ? SK_ColorTRANSPARENT
           : SkColorSetARGB(128, 128, 128, 128);
   settings.highp_threshold_min = 2048;
   // Android WebView handles root layer flings itself.
   settings.ignore_root_layer_flings =
       widget->UsingSynchronousRendererCompositor();
-  settings.always_overscroll = widget->UsingSynchronousRendererCompositor();
   // RGBA_4444 textures are only enabled for low end devices
   // and are disabled for Android WebView as it doesn't support the format.
   settings.use_rgba_4444_textures =
       base::android::SysUtils::IsLowEndDevice() &&
       !widget->UsingSynchronousRendererCompositor() &&
       !cmd->HasSwitch(cc::switches::kDisable4444Textures);
 #elif !defined(OS_MACOSX)
   if (cmd->HasSwitch(switches::kEnableOverlayScrollbars)) {
     settings.scrollbar_animator = cc::LayerTreeSettings::Thinning;
   }
@@ skipping 358 matching lines @@
   widget_->OnSwapBuffersAborted();
 }
 
 void RenderWidgetCompositor::RateLimitSharedMainThreadContext() {
   cc::ContextProvider* provider =
       RenderThreadImpl::current()->SharedMainThreadContextProvider().get();
   provider->Context3d()->rateLimitOffscreenContextCHROMIUM();
 }
 
 }  // namespace content