Enable HarfBuzz by default everywhere except CrOS

ui/gfx/render_text.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 "ui/gfx/render_text.h"
 
 #include <algorithm>
 #include <climits>
 
 #include "base/command_line.h"
@@ skipping 375 matching lines @@
   paint->setAutohinted(params.autohinter);
   paint->setHinting(FontRenderParamsHintingToSkPaintHinting(params.hinting));
 }
 
 }  // namespace internal
 
 RenderText::~RenderText() {
 }
 
 RenderText* RenderText::CreateInstance() {
-#if defined(OS_MACOSX) && defined(TOOLKIT_VIEWS)
-  // Use the more complete HarfBuzz implementation for Views controls on Mac.
-  return new RenderTextHarfBuzz;
-#else
   if (CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kEnableHarfBuzzRenderText)) {
     return new RenderTextHarfBuzz;
   }
+  if (CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kDisableHarfBuzzRenderText)) {
+    return CreateNativeInstance();
+  }
+
+// Disable on Chrome OS. Blocked on http://crbug.com/423791
+#if defined(OS_CHROMEOS)
   return CreateNativeInstance();
+#else
+  return new RenderTextHarfBuzz;
 #endif
 }
 
 void RenderText::SetText(const base::string16& text) {
   DCHECK(!composition_range_.IsValid());
   if (text_ == text)
     return;
   text_ = text;
 
   // Adjust ranged styles and colors to accommodate a new text length.
@@ skipping 966 matching lines @@
   SetDisplayOffset(display_offset_.x() + delta_x);
 }
 
 void RenderText::DrawSelection(Canvas* canvas) {
   const std::vector<Rect> sel = GetSubstringBounds(selection());
   for (std::vector<Rect>::const_iterator i = sel.begin(); i < sel.end(); ++i)
     canvas->FillRect(*i, selection_background_focused_color_);
 }
 
 }  // namespace gfx