Disabled pinch zooming in non-browser Aura windows.

chrome/browser/chromeos/login/webui_login_view.cc

Index: chrome/browser/chromeos/login/webui_login_view.cc
diff --git a/chrome/browser/chromeos/login/webui_login_view.cc b/chrome/browser/chromeos/login/webui_login_view.cc
index 95d87eb7ad5968c11db52e8078f368b09a9ba777..4e5ee81b9832372cfa8975abd887ece943b7b2c1 100644
--- a/chrome/browser/chromeos/login/webui_login_view.cc
+++ b/chrome/browser/chromeos/login/webui_login_view.cc
@@ -36,6 +36,7 @@
 #include "content/public/browser/web_contents.h"
 #include "content/public/browser/web_contents_view.h"
 #include "content/public/browser/web_ui.h"
+#include "third_party/WebKit/public/web/WebInputEvent.h"
 #include "ui/gfx/rect.h"
 #include "ui/gfx/size.h"
 #include "ui/views/controls/webview/webview.h"
@@ -401,6 +402,15 @@ void WebUILoginView::RequestMediaAccessPermission(
     NOTREACHED() << "Media stream not allowed for WebUI";
 }
 
+bool WebUILoginView::PreHandleGestureEvent(
+    content::WebContents* source,
+    const blink::WebGestureEvent& event) {
+  // Disable pinch zooming.
+  return event.type == blink::WebGestureEvent::GesturePinchBegin ||
+      event.type == blink::WebGestureEvent::GesturePinchUpdate ||
+      event.type == blink::WebGestureEvent::GesturePinchEnd;
+}
+
 void WebUILoginView::DidFailProvisionalLoad(
     int64 frame_id,
     const base::string16& frame_unique_name,