Don't DCHECK in EventDispatcher::RemoveAccelerator

components/mus/ws/event_dispatcher.cc

 // Copyright 2015 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/event_dispatcher.h"
 
 #include <set>
 
 #include "base/time/time.h"
 #include "cc/surfaces/surface_hittest.h"
@@ skipping 297 matching lines @@
   for (const auto& pair : accelerators_) {
     if (pair.first == id || matcher.Equals(pair.second))
       return false;
   }
   accelerators_.insert(Entry(id, matcher));
   return true;
 }
 
 void EventDispatcher::RemoveAccelerator(uint32_t id) {
   auto it = accelerators_.find(id);
-  DCHECK(it != accelerators_.end());
-  accelerators_.erase(it);
+  // Clients may pass bogus ids.
+  if (it != accelerators_.end())
+    accelerators_.erase(it);
 }
 
 void EventDispatcher::ProcessEvent(const ui::Event& event) {
   if (!root_)
     return;
 
   if (event.IsKeyEvent()) {
     const ui::KeyEvent* key_event = event.AsKeyEvent();
     if (event.type() == ui::ET_KEY_PRESSED && !key_event->is_char()) {
       uint32_t accelerator = 0u;
@@ skipping 231 matching lines @@
 
 void EventDispatcher::OnWindowDestroyed(ServerWindow* window) {
   CancelPointerEventsToTarget(window);
 
   if (mouse_cursor_source_window_ == window)
     mouse_cursor_source_window_ = nullptr;
 }
 
 }  // namespace ws
 }  // namespace mus