Revert of Replace enable-compositing-for-fixed-position with prefer-compositing-to-lcd-text.

content/renderer/render_view_impl.cc

 // Copyright (c) 2012 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/render_view_impl.h"
 
 #include <algorithm>
 #include <cmath>
 
 #include "base/auto_reset.h"
@@ skipping 381 matching lines @@
 static bool DeviceScaleEnsuresTextQuality(float device_scale_factor) {
 #if defined(OS_ANDROID)
   // On Android, we never have subpixel antialiasing.
   return true;
 #else
   return device_scale_factor > 1.5f;
 #endif
 
 }
 
-static bool PreferCompositingToLCDText(float device_scale_factor) {
+static bool ShouldUseFixedPositionCompositing(float device_scale_factor) {
+  // Compositing for fixed-position elements is dependent on
+  // device_scale_factor if no flag is set. http://crbug.com/172738
   const CommandLine& command_line = *CommandLine::ForCurrentProcess();
-  if (command_line.HasSwitch(switches::kDisablePreferCompositingToLCDText))
+
+  if (command_line.HasSwitch(switches::kDisableCompositingForFixedPosition))
     return false;
-  if (command_line.HasSwitch(switches::kEnablePreferCompositingToLCDText))
+
+  if (command_line.HasSwitch(switches::kEnableCompositingForFixedPosition))
     return true;
+
   return DeviceScaleEnsuresTextQuality(device_scale_factor);
 }
 
 static bool ShouldUseAcceleratedCompositingForOverflowScroll(
     float device_scale_factor) {
   const CommandLine& command_line = *CommandLine::ForCurrentProcess();
 
   if (command_line.HasSwitch(switches::kDisableAcceleratedOverflowScroll))
     return false;
 
@@ skipping 366 matching lines @@
   // If this is a popup, we must wait for the CreatingNew_ACK message before
   // completing initialization.  Otherwise, we can finish it now.
   if (opener_id_ == MSG_ROUTING_NONE) {
     did_show_ = true;
     CompleteInit();
   }
 
   g_view_map.Get().insert(std::make_pair(webview(), this));
   g_routing_id_view_map.Get().insert(std::make_pair(routing_id_, this));
   webview()->setDeviceScaleFactor(device_scale_factor_);
-  webview()->settings()->setPreferCompositingToLCDTextEnabled(
-      PreferCompositingToLCDText(device_scale_factor_));
+  webview()->settings()->setAcceleratedCompositingForFixedPositionEnabled(
+      ShouldUseFixedPositionCompositing(device_scale_factor_));
   webview()->settings()->setAcceleratedCompositingForOverflowScrollEnabled(
       ShouldUseAcceleratedCompositingForOverflowScroll(device_scale_factor_));
   webview()->settings()->setAcceleratedCompositingForTransitionEnabled(
       ShouldUseTransitionCompositing(device_scale_factor_));
   webview()->settings()->setAcceleratedCompositingForFixedRootBackgroundEnabled(
       ShouldUseAcceleratedFixedRootBackground(device_scale_factor_));
   webview()->settings()->setCompositedScrollingForFramesEnabled(
       ShouldUseCompositedScrollingForFrames(device_scale_factor_));
 
   ApplyWebPreferences(webkit_preferences_, webview());
@@ skipping 2950 matching lines @@
   }
   RenderWidget::OnImeConfirmComposition(text,
                                         replacement_range,
                                         keep_selection);
 }
 
 void RenderViewImpl::SetDeviceScaleFactor(float device_scale_factor) {
   RenderWidget::SetDeviceScaleFactor(device_scale_factor);
   if (webview()) {
     webview()->setDeviceScaleFactor(device_scale_factor);
-    webview()->settings()->setPreferCompositingToLCDTextEnabled(
-        PreferCompositingToLCDText(device_scale_factor_));
+    webview()->settings()->setAcceleratedCompositingForFixedPositionEnabled(
+        ShouldUseFixedPositionCompositing(device_scale_factor_));
     webview()->settings()->setAcceleratedCompositingForOverflowScrollEnabled(
         ShouldUseAcceleratedCompositingForOverflowScroll(device_scale_factor_));
     webview()->settings()->setAcceleratedCompositingForTransitionEnabled(
         ShouldUseTransitionCompositing(device_scale_factor_));
     webview()->settings()->
         setAcceleratedCompositingForFixedRootBackgroundEnabled(
             ShouldUseAcceleratedFixedRootBackground(device_scale_factor_));
     webview()->settings()->setCompositedScrollingForFramesEnabled(
         ShouldUseCompositedScrollingForFrames(device_scale_factor_));
   }
@@ skipping 554 matching lines @@
     std::vector<gfx::Size> sizes;
     ConvertToFaviconSizes(icon_urls[i].sizes(), &sizes);
     if (!url.isEmpty())
       urls.push_back(
           FaviconURL(url, ToFaviconType(icon_urls[i].iconType()), sizes));
   }
   SendUpdateFaviconURL(urls);
 }
 
 }  // namespace content