[SP] Enable Slimming Paint by default in Chromium and Blink.

content/browser/renderer_host/render_view_host_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/browser/renderer_host/render_view_host_impl.h"
 
 #include <set>
 #include <string>
 #include <utility>
 #include <vector>
@@ skipping 450 matching lines @@
 
 #if defined(OS_ANDROID)
   prefs.device_supports_mouse = false;
 #endif
 
   prefs.pointer_events_max_touch_points = ui::MaxTouchPoints();
 
   prefs.touch_adjustment_enabled =
       !command_line.HasSwitch(switches::kDisableTouchAdjustment);
 
-  prefs.slimming_paint_enabled =
-      command_line.HasSwitch(switches::kEnableSlimmingPaint);
+  prefs.slimming_paint_enabled = command_line.HasSwitch(
+      switches::kEnableSlimmingPaint) ||
+      !command_line.HasSwitch(switches::kDisableSlimmingPaint);
 
 #if defined(OS_MACOSX) || defined(OS_CHROMEOS)
   bool default_enable_scroll_animator = true;
 #else
   bool default_enable_scroll_animator = false;
 #endif
   prefs.enable_scroll_animator = default_enable_scroll_animator;
   if (command_line.HasSwitch(switches::kEnableSmoothScrolling))
     prefs.enable_scroll_animator = true;
   if (command_line.HasSwitch(switches::kDisableSmoothScrolling))
@@ skipping 945 matching lines @@
     if (!policy->CanReadFile(GetProcess()->GetID(), file))
       policy->GrantReadFile(GetProcess()->GetID(), file);
   }
 }
 
 void RenderViewHostImpl::SelectWordAroundCaret() {
   Send(new ViewMsg_SelectWordAroundCaret(GetRoutingID()));
 }
 
 }  // namespace content