Send synthetic GestureTapDown to focus BrowserPlugin

content/browser/frame_host/render_widget_host_view_guest.cc

Index: content/browser/frame_host/render_widget_host_view_guest.cc
diff --git a/content/browser/frame_host/render_widget_host_view_guest.cc b/content/browser/frame_host/render_widget_host_view_guest.cc
index 2f7ff291f026d98146d677db08171c8e438639c0..1964987c6c41c1cdadd3ee598a60ffe3ceaf740a 100644
--- a/content/browser/frame_host/render_widget_host_view_guest.cc
+++ b/content/browser/frame_host/render_widget_host_view_guest.cc
@@ -175,6 +175,25 @@ void RenderWidgetHostViewGuest::ProcessTouchEvent(
         guest_->GetOwnerRenderWidgetHostView()->GetRenderWidgetHost());
     if (!embedder->GetView()->HasFocus())
       embedder->GetView()->Focus();
+
+    // Since we now route GestureEvents directly to the guest renderer, we need
+    // a way to make sure that the BrowserPlugin in the embedder gets focused so
+    // that keyboard input (which still travels via BrowserPlugin) is routed to
+    // the plugin and thus onwards to the guest.
+    // TODO(wjmaclean): When we remove BrowserPlugin, delete this code.
+    // http://crbug.com/533069
+    if (!HasFocus()) {
+      auto offset = GetViewBounds().origin();
+      blink::WebGestureEvent gesture_tap_down;
+      gesture_tap_down.sourceDevice = blink::WebGestureDeviceTouchscreen;
+      gesture_tap_down.type = blink::WebGestureEvent::GestureTapDown;
+      gesture_tap_down.x = event.touches[0].position.x + offset.x();
+      gesture_tap_down.y = event.touches[0].position.y + offset.y();
+      gesture_tap_down.globalX = event.touches[0].screenPosition.x;
+      gesture_tap_down.globalY = event.touches[0].screenPosition.y;
+      GetOwnerRenderWidgetHostView()->ProcessGestureEvent(gesture_tap_down,
+                                                          ui::LatencyInfo());
+    }
   }
 
   host_->ForwardTouchEventWithLatencyInfo(event, latency);