mus: Disregard windows that explicitly set can_accept_events to be false when sending events.

services/ui/public/interfaces/window_tree.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 ui.mojom;
 
 import "cc/ipc/surface_id.mojom";
 import "services/ui/public/interfaces/cursor.mojom";
 import "services/ui/public/interfaces/event_matcher.mojom";
 import "services/ui/public/interfaces/mus_constants.mojom";
@@ skipping 220 matching lines @@
   // and cursor locking.
 
   // Set text input state for the given window.
   SetWindowTextInputState(uint32 window_id, mojo.TextInputState state);
 
   // Set the input method editor UI (software keyboard, etc) visibility.
   // If state is non-null, the specified window's text input state is updated.
   // Otherwise the existing state is used.
   SetImeVisibility(uint32 window_id, bool visible, mojo.TextInputState? state);
 
+  // Set whether the specified window can accept events. If the specified
+  // window is not accepting events, none of its descendent windows would

[dcheng, 2016/07/13 14:32:59]

Super minor nit: a slightly more standard phrasing is "If a window does not
accept events, none of its descendant windows accept events either."

[riajiang, 2016/07/13 18:03:49]

Done.

+  // be able to accept events either.
+  SetCanAcceptEvents(uint32 window_id, bool accept_events);
+
   // See documentation for WindowTreeClient::OnWindowInputEvent().
   OnWindowInputEventAck(uint32 event_id, EventResult result);
 
   // See description of WindowManager for details.
   GetWindowManagerClient(associated WindowManagerClient& internal);
 
   // Returns a shared memory segment that contains two 16-bit ints packed into a
   // single Atomic32, which represent the current location of the mouse cursor
   // where the location is (x << 16) | y.
   GetCursorLocationMemory() => (handle<shared_buffer> cursor_buffer);
@@ skipping 144 matching lines @@
   // See description of WindowManager for details.
   GetWindowManager(associated WindowManager& internal);
 };
 
 // Mus provides this interface as a way for clients to connect and obtain a
 // WindowTree handle with a supplied WindowTreeClient handle. The
 // WindowTreeClient has no roots, use NewTopLevelWindow() to create one.
 interface WindowTreeFactory {
   CreateWindowTree(WindowTree& tree_request, WindowTreeClient client);
 };