Add blink::WebInputEvent::IsPinchGestureEventType().

extensions/browser/guest_view/mime_handler_view/mime_handler_view_guest.cc

Index: extensions/browser/guest_view/mime_handler_view/mime_handler_view_guest.cc
diff --git a/extensions/browser/guest_view/mime_handler_view/mime_handler_view_guest.cc b/extensions/browser/guest_view/mime_handler_view/mime_handler_view_guest.cc
index 5284e0256887e24d24fde4d020157ccfd57134bc..ebb65d19c60d03e99615f75594a976bd0d136e2f 100644
--- a/extensions/browser/guest_view/mime_handler_view/mime_handler_view_guest.cc
+++ b/extensions/browser/guest_view/mime_handler_view/mime_handler_view_guest.cc
@@ -241,9 +241,7 @@ bool MimeHandlerViewGuest::HandleContextMenu(
 bool MimeHandlerViewGuest::PreHandleGestureEvent(
     WebContents* source,
     const blink::WebGestureEvent& event) {
-  if (event.GetType() == blink::WebGestureEvent::kGesturePinchBegin ||
-      event.GetType() == blink::WebGestureEvent::kGesturePinchUpdate ||
-      event.GetType() == blink::WebGestureEvent::kGesturePinchEnd) {
+  if (blink::WebInputEvent::IsPinchGestureEventType(event.GetType())) {
     // If we're an embedded plugin we drop pinch-gestures to avoid zooming the
     // guest.
     return !is_full_page_plugin();