Mac: Enable two finger double-tap smart zoom

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 1118 matching lines @@
 
   settings->setPinchOverlayScrollbarThickness(
       prefs.pinch_overlay_scrollbar_thickness);
   settings->setRubberBandingOnCompositorThread(
       prefs.rubber_banding_on_compositor_thread);
   settings->setUseSolidColorScrollbars(prefs.use_solid_color_scrollbars);
 
 #if defined(OS_WIN)
   settings->setShowContextMenuOnMouseUp(true);
 #endif
+
+#if defined(OS_MACOSX)
+  settings->setDoubleTapToZoomEnabled(true);
+#endif
 }
 
 /*static*/
 RenderViewImpl* RenderViewImpl::Create(const ViewMsg_New_Params& params,
                                        CompositorDependencies* compositor_deps,
                                        bool was_created_by_renderer) {
   DCHECK(params.view_id != MSG_ROUTING_NONE);
   RenderViewImpl* render_view = NULL;
   if (g_create_render_view_impl)
     render_view = g_create_render_view_impl(params);
@@ skipping 2910 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