Refuse to show Alt+Tab UI concurrently with virtual keyboard.

Overview mode is probably more useful to people who are trying to use
a touch screen. Simply no-op on Alt+Tab when the virtual
keyboard's showing.

BUG=638269

Review-Url: https://codereview.chromium.org/2256283003
Cr-Commit-Position: refs/heads/master@{#414731}

ash/common/accelerators/accelerator_controller.cc

@@ -33,6 +33,7 @@
 #include "base/metrics/user_metrics.h"
 #include "ui/base/accelerators/accelerator.h"
 #include "ui/base/accelerators/accelerator_manager.h"
+#include "ui/keyboard/keyboard_controller.h"
 
 #if defined(OS_CHROMEOS)
 #include "chromeos/dbus/dbus_thread_manager.h"
@@ -130,6 +131,15 @@ bool CanHandleNextIme(ImeControlDelegate* ime_control_delegate) {
   return ime_control_delegate && ime_control_delegate->CanCycleIme();
 }
 
+bool CanHandleCycleMru(const ui::Accelerator& accelerator) {
+  // Don't do anything when Alt+Tab comes from a virtual keyboard. Touchscreen
+  // users have better window switching options. See http://crbug.com/638269
+  keyboard::KeyboardController* keyboard_controller =
+      keyboard::KeyboardController::GetInstance();
+  return !(keyboard_controller && keyboard_controller->keyboard_visible() &&
+           (accelerator.modifiers() & ui::EF_IS_SYNTHESIZED));
+}
+
 // We must avoid showing the Deprecated NEXT_IME notification erronously.
 bool ShouldShowDeprecatedNextImeNotification(
     const ui::Accelerator& previous_accelerator) {
@@ -647,6 +657,9 @@ bool AcceleratorController::CanPerformAction(
   // false should be returned to give the web contents a chance at handling the
   // accelerator.
   switch (action) {
+    case CYCLE_BACKWARD_MRU:
+    case CYCLE_FORWARD_MRU:
+      return CanHandleCycleMru(accelerator);
     case DEBUG_PRINT_LAYER_HIERARCHY:
     case DEBUG_PRINT_VIEW_HIERARCHY:
     case DEBUG_PRINT_WINDOW_HIERARCHY:
@@ -682,8 +695,6 @@ bool AcceleratorController::CanPerformAction(
     case TOGGLE_CAPS_LOCK:
       return CanHandleToggleCapsLock(accelerator, previous_accelerator);
 #endif
-    case CYCLE_BACKWARD_MRU:
-    case CYCLE_FORWARD_MRU:
     case EXIT:
     case FOCUS_NEXT_PANE:
     case FOCUS_PREVIOUS_PANE:
@@ -924,12 +935,12 @@ bool AcceleratorController::ShouldActionConsumeKeyEvent(
 
 AcceleratorController::AcceleratorProcessingRestriction
 AcceleratorController::GetAcceleratorProcessingRestriction(int action) {
-  if (WmShell::Get()->IsPinned() &&
+  WmShell* wm_shell = WmShell::Get();
+  if (wm_shell->IsPinned() &&
       actions_allowed_in_pinned_mode_.find(action) ==
           actions_allowed_in_pinned_mode_.end()) {
     return RESTRICTION_PREVENT_PROCESSING_AND_PROPAGATION;
   }
-  WmShell* wm_shell = WmShell::Get();
   if (!wm_shell->GetSessionStateDelegate()->IsActiveUserSessionStarted() &&
       actions_allowed_at_login_screen_.find(action) ==
           actions_allowed_at_login_screen_.end()) {

chrome/browser/extensions/api/virtual_keyboard_private/chrome_virtual_keyboard_delegate.cc

@@ -155,7 +155,7 @@ bool ChromeVirtualKeyboardDelegate::SendKeyEvent(const std::string& type,
                                           char_value,
                                           key_code,
                                           key_name,
-                                          modifiers,
+                                          modifiers | ui::EF_IS_SYNTHESIZED,
                                           window->GetHost());
 }
 

ui/base/accelerators/accelerator.cc

@@ -27,12 +27,11 @@ namespace ui {
 
 namespace {
 
-const int kEventFlagsMask = ui::EF_SHIFT_DOWN | ui::EF_CONTROL_DOWN |
+const int kModifierMask = ui::EF_SHIFT_DOWN | ui::EF_CONTROL_DOWN |
                             ui::EF_ALT_DOWN | ui::EF_COMMAND_DOWN;
 
-const int kEventFlagsWithRepeatMask = ui::EF_SHIFT_DOWN | ui::EF_CONTROL_DOWN |
-                                      ui::EF_ALT_DOWN | ui::EF_COMMAND_DOWN |
-                                      ui::EF_IS_REPEAT;
+const int kInterestingFlagsMask =
+    kModifierMask | ui::EF_IS_SYNTHESIZED | ui::EF_IS_REPEAT;
 
 }  // namespace
 
@@ -42,13 +41,13 @@ Accelerator::Accelerator()
 Accelerator::Accelerator(KeyboardCode keycode, int modifiers)
     : key_code_(keycode),
       type_(ui::ET_KEY_PRESSED),
-      modifiers_(modifiers & kEventFlagsWithRepeatMask) {}
+      modifiers_(modifiers & kInterestingFlagsMask) {}
 
 Accelerator::Accelerator(const KeyEvent& key_event)
     : key_code_(key_event.key_code()),
       type_(key_event.type()),
       // |modifiers_| may include the repeat flag.
-      modifiers_(key_event.flags() & kEventFlagsWithRepeatMask) {}
+      modifiers_(key_event.flags() & kInterestingFlagsMask) {}
 
 Accelerator::Accelerator(const Accelerator& accelerator) {
   key_code_ = accelerator.key_code_;
@@ -63,7 +62,7 @@ Accelerator::~Accelerator() {
 
 // static
 int Accelerator::MaskOutKeyEventFlags(int flags) {
-  return flags & kEventFlagsMask;
+  return flags & kModifierMask;
 }
 
 Accelerator& Accelerator::operator=(const Accelerator& accelerator) {