Add a workaround for crbug.com/139556.

ash/accelerators/accelerator_controller.cc

 // Copyright (c) 2012 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 "ash/accelerators/accelerator_controller.h"
 
 #include <algorithm>
 #include <cmath>
 #include <string>
 
@@ skipping 292 matching lines @@
   return true;
 }
 
 #endif  // !defined(NDEBUG)
 
 }  // namespace
 
 ////////////////////////////////////////////////////////////////////////////////
 // AcceleratorControllerContext, public:
 
-AcceleratorControllerContext::AcceleratorControllerContext()
-    : repeated_(false),
-      previous_event_type_(ui::ET_UNKNOWN) {
+AcceleratorControllerContext::AcceleratorControllerContext() {
+  current_accelerator_.set_type(ui::ET_UNKNOWN);
+  previous_accelerator_.set_type(ui::ET_UNKNOWN);
 }
 
 void AcceleratorControllerContext::UpdateContext(
     const ui::Accelerator& accelerator) {
-  const ui::Accelerator previous_accelerator = current_accelerator_;
+  previous_accelerator_ = current_accelerator_;
   current_accelerator_ = accelerator;
-
-  // Compute contextual information.
-  repeated_ = previous_accelerator == current_accelerator_;
-  previous_event_type_ = previous_accelerator.type();
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // AcceleratorController, public:
 
 AcceleratorController::AcceleratorController()
     : accelerator_manager_(new ui::AcceleratorManager) {
   Init();
 }
 
@@ skipping 101 matching lines @@
   // should never be suspended.
   const bool gesture_event = key_code == ui::VKEY_UNKNOWN;
 
   // Ignore accelerators invoked as repeated (while holding a key for a long
   // time, if their handling is nonrepeatable.
   if (nonrepeatable_actions_.find(action) != nonrepeatable_actions_.end() &&
       context_.repeated() && !gesture_event) {
     return true;
   }
   // Type of the previous accelerator. Used by NEXT_IME and DISABLE_CAPS_LOCK.
-  const ui::EventType previous_event_type = context_.previous_event_type();
+  const ui::EventType previous_event_type =
+    context_.previous_accelerator().type();
 
   // You *MUST* return true when some action is performed. Otherwise, this
   // function might be called *twice*, via BrowserView::PreHandleKeyboardEvent
   // and BrowserView::HandleKeyboardEvent, for a single accelerator press.
   switch (action) {
     case CYCLE_BACKWARD_MRU:
       if (key_code == ui::VKEY_TAB && shell->delegate())
         shell->delegate()->RecordUserMetricsAction(UMA_ACCEL_PREVWINDOW_TAB);
       return HandleCycleWindowMRU(WindowCycleController::BACKWARD,
                                   accelerator.IsAltDown());
@@ skipping 152 matching lines @@
       }
       break;
     case SHOW_TASK_MANAGER:
       Shell::GetInstance()->delegate()->ShowTaskManager();
       return true;
     case NEXT_IME:
       // This check is necessary e.g. not to process the Shift+Alt+
       // ET_KEY_RELEASED accelerator for Chrome OS (see ash/accelerators/
       // accelerator_controller.cc) when Shift+Alt+Tab is pressed and then Tab
       // is released.
-      if (previous_event_type == ui::ET_KEY_RELEASED) {
+      if (previous_event_type == ui::ET_KEY_RELEASED &&
+          // Workaround for crbug.com/139556. CJK IME users tend to press
+          // Enter (or Space) and Shift+Alt almost at the same time to commit
+          // an IME string and then switch from the IME to the English layout.
+          // This workaround allows the user to trigger NEXT_IME even if the
+          // user presses Shift+Alt before releasing Enter.
+          // TODO(nona|mazda): Fix crbug.com/139556 in a cleaner way.
+          context_.previous_accelerator().key_code() != ui::VKEY_RETURN &&
+          context_.previous_accelerator().key_code() != ui::VKEY_SPACE) {
         // We totally ignore this accelerator.
         // TODO(mazda): Fix crbug.com/158217
         return false;
       }
       if (ime_control_delegate_.get())
         return ime_control_delegate_->HandleNextIme();
       break;
     case PREVIOUS_IME:
       if (ime_control_delegate_.get())
         return ime_control_delegate_->HandlePreviousIme();
@@ skipping 238 matching lines @@
     keyboard_brightness_control_delegate) {
   keyboard_brightness_control_delegate_ =
       keyboard_brightness_control_delegate.Pass();
 }
 
 bool AcceleratorController::CanHandleAccelerators() const {
   return true;
 }
 
 }  // namespace ash