Reland of OOPIF: Route keyboard events to focused frame in the browser process.

content/browser/renderer_host/render_widget_host_view_mac.mm

Index: content/browser/renderer_host/render_widget_host_view_mac.mm
diff --git a/content/browser/renderer_host/render_widget_host_view_mac.mm b/content/browser/renderer_host/render_widget_host_view_mac.mm
index c13e70c5a318e77eddb6fa45a73c492229a25469..ad6db03245d9631f211177441bf4873975a71192 100644
--- a/content/browser/renderer_host/render_widget_host_view_mac.mm
+++ b/content/browser/renderer_host/render_widget_host_view_mac.mm
@@ -2153,6 +2153,15 @@
     return;
   }
 
+  // If there are multiple widgets on the page (such as when there are
+  // out-of-process iframes), pick the one that should process this event.
+  if (widgetHost->delegate()) {
+    RenderWidgetHostImpl* focusedHost =
+        widgetHost->delegate()->GetFocusedRenderWidgetHost();
+    if (focusedHost)
+      widgetHost = focusedHost;
+  }
+
   // Suppress the escape key up event if necessary.
   if (event.windowsKeyCode == ui::VKEY_ESCAPE && suppressNextEscapeKeyUp_) {
     if (event.type == NativeWebKeyboardEvent::KeyUp)