Enforce --enable-pinch flag on Windows.

content/browser/renderer_host/render_widget_host_view_win.cc

Index: content/browser/renderer_host/render_widget_host_view_win.cc
===================================================================
--- content/browser/renderer_host/render_widget_host_view_win.cc	(revision 159005)
+++ content/browser/renderer_host/render_widget_host_view_win.cc	(working copy)
@@ -380,6 +380,12 @@
   DISALLOW_COPY_AND_ASSIGN(TouchEventFromWebTouchPoint);
 };
 
+bool ShouldSendPinchGesture() {
+  static bool pinch_allowed =
+      CommandLine::ForCurrentProcess()->HasSwitch(switches::kEnablePinch);

[Nico, 2012/09/28 04:00:14]

nit: HasSwitch() should be fast, no need to make this static

+  return pinch_allowed;
+}
+
 }  // namespace
 
 const wchar_t kRenderWidgetHostHWNDClass[] = L"Chrome_RenderWidgetHostHWND";
@@ -2785,6 +2791,15 @@
   if (!render_widget_host_)
     return false;
 
+  // Pinch gestures are disabled by default on windows desktop. See
+  // crbug.com/128477 and crbug.com/148816
+  if ((gesture->type() == ui::ET_GESTURE_PINCH_BEGIN ||
+      gesture->type() == ui::ET_GESTURE_PINCH_UPDATE ||
+      gesture->type() == ui::ET_GESTURE_PINCH_END) &&
+      !ShouldSendPinchGesture()) {
+    return true;
+  }
+
   WebKit::WebGestureEvent web_gesture = CreateWebGestureEvent(m_hWnd, *gesture);
   if (web_gesture.type == WebKit::WebGestureEvent::Undefined)
     return false;