Make PageScaleFactor work for oopif subframes.

content/browser/renderer_host/render_widget_host_input_event_router.cc

Index: content/browser/renderer_host/render_widget_host_input_event_router.cc
diff --git a/content/browser/renderer_host/render_widget_host_input_event_router.cc b/content/browser/renderer_host/render_widget_host_input_event_router.cc
index cb96ee2baaebbe5c11a0de76ae583bf83fb0c90c..aa6e26433b60afe423d848caac84237e2a54e267 100644
--- a/content/browser/renderer_host/render_widget_host_input_event_router.cc
+++ b/content/browser/renderer_host/render_widget_host_input_event_router.cc
@@ -35,6 +35,12 @@ blink::WebGestureEvent DummyGestureScrollUpdate(double timeStampSeconds) {
                                 timeStampSeconds);
 }
 
+bool IsGesturePinchEvent(const blink::WebGestureEvent* event) {
+  return event->type() == blink::WebInputEvent::GesturePinchBegin ||
+         event->type() == blink::WebInputEvent::GesturePinchUpdate ||
+         event->type() == blink::WebInputEvent::GesturePinchEnd;
+}
+
 }  // anonymous namespace
 
 namespace content {
@@ -689,6 +695,18 @@ void RenderWidgetHostInputEventRouter::RouteTouchscreenGestureEvent(
 
   if (in_touchscreen_gesture_pinch_) {
     root_view->ProcessGestureEvent(*event, latency);
+    if (IsGesturePinchEvent(event)) {
+      // Broadcast the pinch events to all subframes so they can update their
+      // PageScales with the deltas in the events. We don't broadcast to
+      // RenderWidgetHostViewGuest as it has a separate mechanism for
+      // propagating page scaleg

[kenrb, 2017/01/24 17:13:27]

nit: Typo.

[wjmaclean, 2017/01/24 18:24:26]

Done.

+      for (auto entry : owner_map_) {
+        if (entry.second != root_view &&
+            !entry.second->IsRenderWidgetHostViewGuest()) {
+          entry.second->ProcessGestureEvent(*event, latency);

[kenrb, 2017/01/24 17:13:27]

Will this eventually get removed? It feels weird to be dispatching these events
to every process, but it would be fine if this won't be necessary after
Salamander ships.

[wjmaclean, 2017/01/24 18:24:26]

Yes, this will disappear with Salamander.

[kenrb, 2017/01/24 18:47:30]

This warrants a TODO, marking it as temporary, then.

+        }
+      }
+    }
     if (event->type() == blink::WebInputEvent::GesturePinchEnd) {
       in_touchscreen_gesture_pinch_ = false;
       // If the root view wasn't already receiving the gesture stream, then we