mus: Don't allow SetEventObserver to monitor key events

components/mus/ws/window_tree_unittest.cc

 // 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.
 
 #include "components/mus/ws/window_tree.h"
 
 #include <stdint.h>
 
 #include <string>
 #include <vector>
@@ skipping 366 matching lines @@
       .SetEventObserver(CreateEventMatcher(mojom::EventType::POINTER_UP), 222u);
 
   // An event is observed by the wm tree, but not by the other user's tree.
   DispatchEventAndAckImmediately(CreatePointerUpEvent(5, 5));
   ASSERT_EQ(1u, wm_client()->tracker()->changes()->size());
   EXPECT_EQ("InputEvent window=0,3 event_action=6 event_observer_id=111",
             SingleChangeToDescription(*wm_client()->tracker()->changes()));
   ASSERT_EQ(0u, other_binding->client()->tracker()->changes()->size());
 }
 
-// Tests that an event observer can receive events that have no target window.
-TEST_F(WindowTreeTest, SetEventObserverNoTarget) {

[James Cook, 2016/05/25 20:59:41]

I removed this test because the remaining event types supported by
SetEventObserver always have a target -- they are all mouse or touch events, and
if they don't hit a client window they are dispatched to the root window.

+// Tests that an event observer cannot observe keystrokes.
+TEST_F(WindowTreeTest, SetEventObserverKeyEventsDisallowed) {
   WindowTreeTestApi(wm_tree()).SetEventObserver(
-      CreateEventMatcher(mojom::EventType::KEY_RELEASED), 111u);
-  ui::KeyEvent key(ui::ET_KEY_RELEASED, ui::VKEY_A, ui::EF_NONE);
-  DispatchEventAndAckImmediately(key);
-  EXPECT_EQ("EventObserved event_action=2 event_observer_id=111",
-            SingleChangeToDescription(*wm_client()->tracker()->changes()));
+      CreateEventMatcher(mojom::EventType::KEY_PRESSED), 111u);
+  ui::KeyEvent key_pressed(ui::ET_KEY_PRESSED, ui::VKEY_A, ui::EF_NONE);
+  DispatchEventAndAckImmediately(key_pressed);
+  EXPECT_EQ(0u, wm_client()->tracker()->changes()->size());
+
+  WindowTreeTestApi(wm_tree()).SetEventObserver(
+      CreateEventMatcher(mojom::EventType::KEY_RELEASED), 222u);
+  ui::KeyEvent key_released(ui::ET_KEY_RELEASED, ui::VKEY_A, ui::EF_NONE);
+  DispatchEventAndAckImmediately(key_released);
+  EXPECT_EQ(0u, wm_client()->tracker()->changes()->size());
 }
 
 TEST_F(WindowTreeTest, CursorChangesWhenMouseOverWindowAndWindowSetsCursor) {
   TestWindowTreeClient* embed_connection = nullptr;
   WindowTree* tree = nullptr;
   ServerWindow* window = nullptr;
   EXPECT_NO_FATAL_FAILURE(
       SetupEventTargeting(&embed_connection, &tree, &window));
 
   // Like in BasicInputEventTarget, we send a pointer down event to be
@@ skipping 596 matching lines @@
   ASSERT_NE(new_opacity, unknown_window.opacity());
 
   EXPECT_FALSE(tree->SetWindowOpacity(
       ClientWindowId(WindowIdToTransportId(window_id)), new_opacity));
   EXPECT_NE(new_opacity, unknown_window.opacity());
 }
 
 }  // namespace test
 }  // namespace ws
 }  // namespace mus