Change allowed bindings to be per RenderFrame instead of per RenderView.

content/common/frame.mojom

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 module content.mojom;
 
 import "services/service_manager/public/interfaces/interface_provider.mojom";
 
 // The name of the InterfaceProviderSpec in service manifests used by the
 // frame tree to expose frame-specific interfaces between renderer and browser.
 const string kNavigation_FrameSpec = "navigation:frame";
 
 // Implemented by the frame provider (e.g. renderer processes).
 interface Frame {
   GetInterfaceProvider(service_manager.mojom.InterfaceProvider& interfaces);
 };
 
 // Implemented by the frame server (i.e. the browser process).
 interface FrameHost {
   GetInterfaceProvider(service_manager.mojom.InterfaceProvider& interfaces);
 };
 
 // Implemented by a service that provides implementations of the Frame
 // interface. (e.g. renderer processes).
 interface FrameFactory {
   CreateFrame(int32 frame_routing_id, Frame& frame, FrameHost host);
 };
+
+interface FrameBindingsControl {

[dcheng, 2017/01/20 08:29:27]

Nit: it might be nice to group the browser and renderer interfaces together...
I'm not sure.

Also, I'm curious: why a separate interface? Is it just to make the Frame
interface itself more modular? It makes it a bit harder to tell how the
different interfaces here are related: for example, I think that this is
actually associated with Frame, but I wouldn't be able to tell from just reading
the mojom.

[Sam McNally, 2017/01/23 03:20:28]

Done.
It's because AllowBindings() needs to be associated with the legacy IPC channel,
but GetInterfaceProvider() needs to support queuing (which associated interfaces
don't allow).

+  // Used to tell a render frame whether it should expose various bindings
+  // that allow JS content extended privileges.  See BindingsPolicy for valid
+  // flag values.
+  AllowBindings(int32 enabled_bindings_flags);
+};