Convert sticky keys to a chromeos::EventRewriter phase.

BUG=354035
TEST=unit_tests,ash_unittests,manual
R=sadrul@chromium.org,derat@chromium.org

Review URL: https://codereview.chromium.org/255033003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@278342 0039d316-1c4b-4281-b951-d872f2087c98

ash/shell.cc

@@ -889,13 +889,6 @@ void Shell::Init(const ShellInitParams& init_params) {
 
   // The order in which event filters are added is significant.
 
-#if defined(OS_CHROMEOS)
-  // The StickyKeysController also rewrites events and must be added
-  // before observers, but after the EventRewriterEventFilter.
-  sticky_keys_controller_.reset(new StickyKeysController);
-  AddPreTargetHandler(sticky_keys_controller_.get());
-#endif
-
   // wm::UserActivityDetector passes events to observers, so let them get
   // rewritten first.
   user_activity_detector_.reset(new ::wm::UserActivityDetector);
@@ -930,6 +923,10 @@ void Shell::Init(const ShellInitParams& init_params) {
     keyboard::InitializeKeyboard();
 #endif
 
+#if defined(OS_CHROMEOS)
+  sticky_keys_controller_.reset(new StickyKeysController);
+#endif
+
   lock_state_controller_.reset(new LockStateController);
   power_button_controller_.reset(new PowerButtonController(
       lock_state_controller_.get()));

ash/sticky_keys/sticky_keys_overlay_unittest.cc

@@ -7,47 +7,14 @@
 #include "ash/shell.h"
 #include "ash/sticky_keys/sticky_keys_controller.h"
 #include "ash/test/ash_test_base.h"
-#include "base/memory/scoped_ptr.h"
-#include "ui/aura/window_tree_host.h"
 #include "ui/events/event.h"
-#include "ui/events/event_processor.h"
 
 namespace ash {
 
 class StickyKeysOverlayTest : public test::AshTestBase {
  public:
-  StickyKeysOverlayTest() :
-      controller_(NULL),
-      overlay_(NULL) {}
-
+  StickyKeysOverlayTest() {}
   virtual ~StickyKeysOverlayTest() {}
-
-  virtual void SetUp() OVERRIDE {
-    test::AshTestBase::SetUp();
-
-    controller_ = Shell::GetInstance()->sticky_keys_controller();
-    controller_->Enable(true);
-    overlay_ = controller_->GetOverlayForTest();
-    ASSERT_TRUE(overlay_);
-  }
-
-  void PressAndReleaseKey(ui::KeyboardCode code) {
-    SendKeyEvent(ui::ET_KEY_PRESSED, code);
-    SendKeyEvent(ui::ET_KEY_RELEASED, code);
-  }
-
-  void SendKeyEvent(ui::EventType type, ui::KeyboardCode code) {
-    ui::KeyEvent event(type, code, 0, false);
-    ui::Event::DispatcherApi dispatcher(&event);
-    dispatcher.set_target(Shell::GetInstance()->GetPrimaryRootWindow());
-
-    ui::EventDispatchDetails details = Shell::GetPrimaryRootWindow()->
-        GetHost()->event_processor()->OnEventFromSource(&event);
-    CHECK(!details.dispatcher_destroyed);
-  }
-
-  StickyKeysController* controller_;
-  StickyKeysOverlay* overlay_;
 };
 
 TEST_F(StickyKeysOverlayTest, OverlayVisibility) {
@@ -71,168 +38,7 @@ TEST_F(StickyKeysOverlayTest, ModifierKeyState) {
             overlay.GetModifierKeyState(ui::EF_CONTROL_DOWN));
 }
 
-TEST_F(StickyKeysOverlayTest, OneModifierEnabled) {
-  EXPECT_FALSE(overlay_->is_visible());
-  EXPECT_EQ(STICKY_KEY_STATE_DISABLED,
-            overlay_->GetModifierKeyState(ui::EF_CONTROL_DOWN));
-
-  // Pressing modifier key should show overlay.
-  PressAndReleaseKey(ui::VKEY_CONTROL);
-  EXPECT_TRUE(overlay_->is_visible());
-  EXPECT_EQ(STICKY_KEY_STATE_ENABLED,
-            overlay_->GetModifierKeyState(ui::EF_CONTROL_DOWN));
-
-  // Pressing a normal key should hide overlay.
-  PressAndReleaseKey(ui::VKEY_T);
-  EXPECT_FALSE(overlay_->is_visible());
-  EXPECT_EQ(STICKY_KEY_STATE_DISABLED,
-            overlay_->GetModifierKeyState(ui::EF_CONTROL_DOWN));
-}
-
-TEST_F(StickyKeysOverlayTest, TwoModifiersEnabled) {
-  EXPECT_FALSE(overlay_->is_visible());
-  EXPECT_EQ(STICKY_KEY_STATE_DISABLED,
-            overlay_->GetModifierKeyState(ui::EF_CONTROL_DOWN));
-  EXPECT_EQ(STICKY_KEY_STATE_DISABLED,
-            overlay_->GetModifierKeyState(ui::EF_SHIFT_DOWN));
-
-  // Pressing two modifiers should show overlay.
-  PressAndReleaseKey(ui::VKEY_SHIFT);
-  PressAndReleaseKey(ui::VKEY_CONTROL);
-  EXPECT_TRUE(overlay_->is_visible());
-  EXPECT_EQ(STICKY_KEY_STATE_ENABLED,
-            overlay_->GetModifierKeyState(ui::EF_SHIFT_DOWN));
-  EXPECT_EQ(STICKY_KEY_STATE_ENABLED,
-            overlay_->GetModifierKeyState(ui::EF_CONTROL_DOWN));
-
-  // Pressing a normal key should hide overlay.
-  PressAndReleaseKey(ui::VKEY_N);
-  EXPECT_FALSE(overlay_->is_visible());
-  EXPECT_EQ(STICKY_KEY_STATE_DISABLED,
-            overlay_->GetModifierKeyState(ui::EF_CONTROL_DOWN));
-  EXPECT_EQ(STICKY_KEY_STATE_DISABLED,
-            overlay_->GetModifierKeyState(ui::EF_SHIFT_DOWN));
-}
-
-TEST_F(StickyKeysOverlayTest, LockedModifier) {
-  EXPECT_FALSE(overlay_->is_visible());
-  EXPECT_EQ(STICKY_KEY_STATE_DISABLED,
-            overlay_->GetModifierKeyState(ui::EF_ALT_DOWN));
-
-  // Pressing a modifier key twice should lock modifier and show overlay.
-  PressAndReleaseKey(ui::VKEY_LMENU);
-  PressAndReleaseKey(ui::VKEY_LMENU);
-  EXPECT_TRUE(overlay_->is_visible());
-  EXPECT_EQ(STICKY_KEY_STATE_LOCKED,
-            overlay_->GetModifierKeyState(ui::EF_ALT_DOWN));
-
-  // Pressing a normal key should not hide overlay.
-  PressAndReleaseKey(ui::VKEY_D);
-  EXPECT_TRUE(overlay_->is_visible());
-  EXPECT_EQ(STICKY_KEY_STATE_LOCKED,
-            overlay_->GetModifierKeyState(ui::EF_ALT_DOWN));
-}
-
-TEST_F(StickyKeysOverlayTest, LockedAndNormalModifier) {
-  EXPECT_FALSE(overlay_->is_visible());
-  EXPECT_EQ(STICKY_KEY_STATE_DISABLED,
-            overlay_->GetModifierKeyState(ui::EF_CONTROL_DOWN));
-  EXPECT_EQ(STICKY_KEY_STATE_DISABLED,
-            overlay_->GetModifierKeyState(ui::EF_SHIFT_DOWN));
-
-  // Pressing a modifier key twice should lock modifier and show overlay.
-  PressAndReleaseKey(ui::VKEY_CONTROL);
-  PressAndReleaseKey(ui::VKEY_CONTROL);
-  EXPECT_TRUE(overlay_->is_visible());
-  EXPECT_EQ(STICKY_KEY_STATE_LOCKED,
-            overlay_->GetModifierKeyState(ui::EF_CONTROL_DOWN));
-
-  // Pressing another modifier key should still show overlay.
-  PressAndReleaseKey(ui::VKEY_SHIFT);
-  EXPECT_TRUE(overlay_->is_visible());
-  EXPECT_EQ(STICKY_KEY_STATE_LOCKED,
-            overlay_->GetModifierKeyState(ui::EF_CONTROL_DOWN));
-  EXPECT_EQ(STICKY_KEY_STATE_ENABLED,
-            overlay_->GetModifierKeyState(ui::EF_SHIFT_DOWN));
-
-  // Pressing a normal key should not hide overlay but disable normal modifier.
-  PressAndReleaseKey(ui::VKEY_D);
-  EXPECT_TRUE(overlay_->is_visible());
-  EXPECT_EQ(STICKY_KEY_STATE_LOCKED,
-            overlay_->GetModifierKeyState(ui::EF_CONTROL_DOWN));
-  EXPECT_EQ(STICKY_KEY_STATE_DISABLED,
-            overlay_->GetModifierKeyState(ui::EF_SHIFT_DOWN));
-}
-
-TEST_F(StickyKeysOverlayTest, ModifiersDisabled) {
-  EXPECT_FALSE(overlay_->is_visible());
-  EXPECT_EQ(STICKY_KEY_STATE_DISABLED,
-            overlay_->GetModifierKeyState(ui::EF_CONTROL_DOWN));
-  EXPECT_EQ(STICKY_KEY_STATE_DISABLED,
-            overlay_->GetModifierKeyState(ui::EF_SHIFT_DOWN));
-  EXPECT_EQ(STICKY_KEY_STATE_DISABLED,
-            overlay_->GetModifierKeyState(ui::EF_ALT_DOWN));
-
-  // Enable modifiers.
-  PressAndReleaseKey(ui::VKEY_CONTROL);
-  PressAndReleaseKey(ui::VKEY_SHIFT);
-  PressAndReleaseKey(ui::VKEY_SHIFT);
-  PressAndReleaseKey(ui::VKEY_LMENU);
-
-  EXPECT_TRUE(overlay_->is_visible());
-  EXPECT_EQ(STICKY_KEY_STATE_ENABLED,
-            overlay_->GetModifierKeyState(ui::EF_CONTROL_DOWN));
-  EXPECT_EQ(STICKY_KEY_STATE_LOCKED,
-            overlay_->GetModifierKeyState(ui::EF_SHIFT_DOWN));
-  EXPECT_EQ(STICKY_KEY_STATE_ENABLED,
-            overlay_->GetModifierKeyState(ui::EF_ALT_DOWN));
-
-  // Disable modifiers and overlay should be hidden.
-  PressAndReleaseKey(ui::VKEY_CONTROL);
-  PressAndReleaseKey(ui::VKEY_CONTROL);
-  PressAndReleaseKey(ui::VKEY_SHIFT);
-  PressAndReleaseKey(ui::VKEY_LMENU);
-  PressAndReleaseKey(ui::VKEY_LMENU);
-
-  EXPECT_FALSE(overlay_->is_visible());
-  EXPECT_EQ(STICKY_KEY_STATE_DISABLED,
-            overlay_->GetModifierKeyState(ui::EF_CONTROL_DOWN));
-  EXPECT_EQ(STICKY_KEY_STATE_DISABLED,
-            overlay_->GetModifierKeyState(ui::EF_SHIFT_DOWN));
-  EXPECT_EQ(STICKY_KEY_STATE_DISABLED,
-            overlay_->GetModifierKeyState(ui::EF_ALT_DOWN));
-}
-
-TEST_F(StickyKeysOverlayTest, ModifierVisibility) {
-  // All but AltGr and Mod3 should initially be visible.
-  EXPECT_TRUE(overlay_->GetModifierVisible(ui::EF_CONTROL_DOWN));
-  EXPECT_TRUE(overlay_->GetModifierVisible(ui::EF_SHIFT_DOWN));
-  EXPECT_TRUE(overlay_->GetModifierVisible(ui::EF_ALT_DOWN));
-  EXPECT_FALSE(overlay_->GetModifierVisible(ui::EF_ALTGR_DOWN));
-  EXPECT_FALSE(overlay_->GetModifierVisible(ui::EF_MOD3_DOWN));
-
-  // Turn all modifiers on.
-  controller_->SetModifiersEnabled(true, true);
-  EXPECT_TRUE(overlay_->GetModifierVisible(ui::EF_CONTROL_DOWN));
-  EXPECT_TRUE(overlay_->GetModifierVisible(ui::EF_SHIFT_DOWN));
-  EXPECT_TRUE(overlay_->GetModifierVisible(ui::EF_ALT_DOWN));
-  EXPECT_TRUE(overlay_->GetModifierVisible(ui::EF_ALTGR_DOWN));
-  EXPECT_TRUE(overlay_->GetModifierVisible(ui::EF_MOD3_DOWN));
-
-  // Turn off Mod3.
-  controller_->SetModifiersEnabled(false, true);
-  EXPECT_TRUE(overlay_->GetModifierVisible(ui::EF_ALTGR_DOWN));
-  EXPECT_FALSE(overlay_->GetModifierVisible(ui::EF_MOD3_DOWN));
-
-  // Turn off AltGr.
-  controller_->SetModifiersEnabled(true, false);
-  EXPECT_FALSE(overlay_->GetModifierVisible(ui::EF_ALTGR_DOWN));
-  EXPECT_TRUE(overlay_->GetModifierVisible(ui::EF_MOD3_DOWN));
-
-  // Turn off AltGr and Mod3.
-  controller_->SetModifiersEnabled(false, false);
-  EXPECT_FALSE(overlay_->GetModifierVisible(ui::EF_ALTGR_DOWN));
-  EXPECT_FALSE(overlay_->GetModifierVisible(ui::EF_MOD3_DOWN));
-}
+// Additional sticky key overlay tests that depend on chromeos::EventRewriter
+// are now in chrome/browser/chromeos/events/event_rewriter_unittest.cc .
 
 }  // namespace ash

chrome/browser/chromeos/chrome_browser_main_chromeos.cc

@@ -730,11 +730,6 @@ void ChromeBrowserMainPartsChromeos::PreBrowserStart() {
   // Start the CrOS input device UMA watcher
   DeviceUMA::GetInstance();
 #endif
-  keyboard_event_rewriters_.reset(new EventRewriterController());
-  keyboard_event_rewriters_->AddEventRewriter(
-      scoped_ptr<ui::EventRewriter>(new KeyboardDrivenEventRewriter()));
-  keyboard_event_rewriters_->AddEventRewriter(
-      scoped_ptr<ui::EventRewriter>(new EventRewriter()));
 
   // -- This used to be in ChromeBrowserMainParts::PreMainMessageLoopRun()
   // -- immediately after ChildProcess::WaitForDebugger().
@@ -757,7 +752,13 @@ void ChromeBrowserMainPartsChromeos::PostBrowserStart() {
   // These are dependent on the ash::Shell singleton already having been
   // initialized.
   power_button_observer_.reset(new PowerButtonObserver);
-  data_promo_notification_.reset(new DataPromoNotification()),
+  data_promo_notification_.reset(new DataPromoNotification());
+
+  keyboard_event_rewriters_.reset(new EventRewriterController());
+  keyboard_event_rewriters_->AddEventRewriter(
+      scoped_ptr<ui::EventRewriter>(new KeyboardDrivenEventRewriter()));
+  keyboard_event_rewriters_->AddEventRewriter(scoped_ptr<ui::EventRewriter>(
+      new EventRewriter(ash::Shell::GetInstance()->sticky_keys_controller())));
   keyboard_event_rewriters_->Init();
 
   ChromeBrowserMainPartsLinux::PostBrowserStart();

chrome/browser/chromeos/events/event_rewriter.cc

@@ -6,10 +6,12 @@
 
 #include <vector>
 
+#include "ash/sticky_keys/sticky_keys_controller.h"
 #include "ash/wm/window_state.h"
 #include "ash/wm/window_util.h"
 #include "base/command_line.h"
 #include "base/logging.h"
+#include "base/macros.h"
 #include "base/prefs/pref_service.h"
 #include "base/strings/string_util.h"
 #include "base/sys_info.h"
@@ -153,12 +155,24 @@ void UpdateX11EventMask(int ui_flags, unsigned int* x_flags) {
 }
 #endif
 
+bool IsSendEvent(const ui::Event& event) {
+#if defined(USE_X11)
+  // Do not rewrite an event sent by ui_controls::SendKeyPress(). See
+  // crbug.com/136465.
+  XEvent* xev = event.native_event();
+  if (xev && xev->xany.send_event)
+    return true;
+#endif
+  return false;
+}
+
 }  // namespace
 
-EventRewriter::EventRewriter()
+EventRewriter::EventRewriter(ash::StickyKeysController* sticky_keys_controller)
     : last_device_id_(kBadDeviceId),
       ime_keyboard_for_testing_(NULL),
-      pref_service_for_testing_(NULL) {
+      pref_service_for_testing_(NULL),
+      sticky_keys_controller_(sticky_keys_controller) {
 #if defined(USE_X11)
   ui::PlatformEventSource::GetInstance()->AddPlatformEventObserver(this);
   if (base::SysInfo::IsRunningOnChromeOS()) {
@@ -190,35 +204,38 @@ void EventRewriter::RewriteLocatedEventForTesting(const ui::Event& event,
 ui::EventRewriteStatus EventRewriter::RewriteEvent(
     const ui::Event& event,
     scoped_ptr<ui::Event>* rewritten_event) {
-#if defined(USE_X11)
-  // Do not rewrite an event sent by ui_controls::SendKeyPress(). See
-  // crbug.com/136465.
-  XEvent* xev = event.native_event();
-  if (xev && xev->xany.send_event)
-    return ui::EVENT_REWRITE_CONTINUE;
-#endif
-  switch (event.type()) {
-    case ui::ET_KEY_PRESSED:
-    case ui::ET_KEY_RELEASED:
-      return RewriteKeyEvent(static_cast<const ui::KeyEvent&>(event),
+  if ((event.type() == ui::ET_KEY_PRESSED) ||
+      (event.type() == ui::ET_KEY_RELEASED)) {
+    return RewriteKeyEvent(static_cast<const ui::KeyEvent&>(event),
+                           rewritten_event);
+  }
+  if (event.IsMouseEvent()) {
+    return RewriteMouseEvent(static_cast<const ui::MouseEvent&>(event),
                              rewritten_event);
-    case ui::ET_MOUSE_PRESSED:
-    case ui::ET_MOUSE_RELEASED:
-      return RewriteMouseEvent(static_cast<const ui::MouseEvent&>(event),
-                               rewritten_event);
-    case ui::ET_TOUCH_PRESSED:
-    case ui::ET_TOUCH_RELEASED:
-      return RewriteTouchEvent(static_cast<const ui::TouchEvent&>(event),
-                               rewritten_event);
-    default:
-      return ui::EVENT_REWRITE_CONTINUE;
   }
-  NOTREACHED();
+  if ((event.type() == ui::ET_TOUCH_PRESSED) ||
+      (event.type() == ui::ET_TOUCH_RELEASED)) {
+    return RewriteTouchEvent(static_cast<const ui::TouchEvent&>(event),
+                             rewritten_event);
+  }
+  if (event.IsScrollEvent()) {
+    return RewriteScrollEvent(static_cast<const ui::ScrollEvent&>(event),
+                              rewritten_event);
+  }
+  return ui::EVENT_REWRITE_CONTINUE;
 }
 
 ui::EventRewriteStatus EventRewriter::NextDispatchEvent(
     const ui::Event& last_event,
     scoped_ptr<ui::Event>* new_event) {
+  if (sticky_keys_controller_) {
+    // In the case of sticky keys, we know what the events obtained here are:
+    // modifier key releases that match the ones previously discarded. So, we
+    // know that they don't have to be passed through the post-sticky key
+    // rewriting phases, |RewriteExtendedKeys()| and |RewriteFunctionKeys()|,
+    // because those phases do nothing with modifier key releases.
+    return sticky_keys_controller_->NextDispatchEvent(new_event);
+  }
   NOTREACHED();
   return ui::EVENT_REWRITE_CONTINUE;
 }
@@ -333,14 +350,33 @@ ui::EventRewriteStatus EventRewriter::RewriteKeyEvent(
     const ui::KeyEvent& key_event,
     scoped_ptr<ui::Event>* rewritten_event) {
   MutableKeyState state = {key_event.flags(), key_event.key_code()};
-  RewriteModifierKeys(key_event, &state);
-  RewriteNumPadKeys(key_event, &state);
-  RewriteExtendedKeys(key_event, &state);
-  RewriteFunctionKeys(key_event, &state);
+  bool is_send_event = IsSendEvent(key_event);
+  if (!is_send_event) {
+    RewriteModifierKeys(key_event, &state);
+    RewriteNumPadKeys(key_event, &state);
+  }
+  ui::EventRewriteStatus status = ui::EVENT_REWRITE_CONTINUE;
+  if (sticky_keys_controller_) {
+    status = sticky_keys_controller_->RewriteKeyEvent(
+        key_event, state.key_code, &state.flags);
+    if (status == ui::EVENT_REWRITE_DISCARD)
+      return ui::EVENT_REWRITE_DISCARD;
+  }
+  if (!is_send_event) {
+    RewriteExtendedKeys(key_event, &state);
+    RewriteFunctionKeys(key_event, &state);
+  }
   if ((key_event.flags() == state.flags) &&
-      (key_event.key_code() == state.key_code)) {
+      (key_event.key_code() == state.key_code) &&
+      (status == ui::EVENT_REWRITE_CONTINUE)) {
     return ui::EVENT_REWRITE_CONTINUE;
   }
+  // Sticky keys may have returned a result other than |EVENT_REWRITE_CONTINUE|,
+  // in which case we need to preserve that return status. Alternatively, we
+  // might be here because key_event changed, in which case we need to return
+  // |EVENT_REWRITE_REWRITTEN|.
+  if (status == ui::EVENT_REWRITE_CONTINUE)
+    status = ui::EVENT_REWRITE_REWRITTEN;
   ui::KeyEvent* rewritten_key_event = new ui::KeyEvent(key_event);
   rewritten_event->reset(rewritten_key_event);
   rewritten_key_event->set_flags(state.flags);
@@ -360,16 +396,26 @@ ui::EventRewriteStatus EventRewriter::RewriteKeyEvent(
                              state.key_code, state.flags & ui::EF_SHIFT_DOWN));
   }
 #endif
-  return ui::EVENT_REWRITE_REWRITTEN;
+  return status;
 }
 
 ui::EventRewriteStatus EventRewriter::RewriteMouseEvent(
     const ui::MouseEvent& mouse_event,
     scoped_ptr<ui::Event>* rewritten_event) {
   int flags = mouse_event.flags();
-  RewriteLocatedEvent(mouse_event, &flags);
-  if (mouse_event.flags() == flags)
+  if ((mouse_event.type() == ui::ET_MOUSE_PRESSED) ||
+      (mouse_event.type() == ui::ET_MOUSE_RELEASED)) {
+    RewriteLocatedEvent(mouse_event, &flags);
+  }
+  ui::EventRewriteStatus status = ui::EVENT_REWRITE_CONTINUE;
+  if (sticky_keys_controller_)
+    status = sticky_keys_controller_->RewriteMouseEvent(mouse_event, &flags);
+  if ((mouse_event.flags() == flags) &&
+      (status == ui::EVENT_REWRITE_CONTINUE)) {
     return ui::EVENT_REWRITE_CONTINUE;
+  }
+  if (status == ui::EVENT_REWRITE_CONTINUE)
+    status = ui::EVENT_REWRITE_REWRITTEN;
   ui::MouseEvent* rewritten_mouse_event = new ui::MouseEvent(mouse_event);
   rewritten_event->reset(rewritten_mouse_event);
   rewritten_mouse_event->set_flags(flags);
@@ -397,7 +443,7 @@ ui::EventRewriteStatus EventRewriter::RewriteMouseEvent(
     }
   }
 #endif
-  return ui::EVENT_REWRITE_REWRITTEN;
+  return status;
 }
 
 ui::EventRewriteStatus EventRewriter::RewriteTouchEvent(
@@ -424,6 +470,32 @@ ui::EventRewriteStatus EventRewriter::RewriteTouchEvent(
   return ui::EVENT_REWRITE_REWRITTEN;
 }
 
+ui::EventRewriteStatus EventRewriter::RewriteScrollEvent(
+    const ui::ScrollEvent& scroll_event,
+    scoped_ptr<ui::Event>* rewritten_event) {
+  int flags = scroll_event.flags();
+  ui::EventRewriteStatus status = ui::EVENT_REWRITE_CONTINUE;
+  if (sticky_keys_controller_)
+    status = sticky_keys_controller_->RewriteScrollEvent(scroll_event, &flags);
+  if (status == ui::EVENT_REWRITE_CONTINUE)
+    return status;
+  ui::ScrollEvent* rewritten_scroll_event = new ui::ScrollEvent(scroll_event);
+  rewritten_event->reset(rewritten_scroll_event);
+  rewritten_scroll_event->set_flags(flags);
+#if defined(USE_X11)
+  XEvent* xev = rewritten_scroll_event->native_event();
+  if (xev) {
+    XIDeviceEvent* xievent = static_cast<XIDeviceEvent*>(xev->xcookie.data);
+    if (xievent) {
+      UpdateX11EventMask(
+          rewritten_scroll_event->flags(),
+          reinterpret_cast<unsigned int*>(&xievent->mods.effective));
+    }
+  }
+#endif
+  return status;
+}
+
 void EventRewriter::RewriteModifierKeys(const ui::KeyEvent& key_event,
                                         MutableKeyState* state) {
   DCHECK(key_event.type() == ui::ET_KEY_PRESSED ||

chrome/browser/chromeos/events/event_rewriter.h

@@ -23,6 +23,10 @@ typedef union _XEvent XEvent;
 
 class PrefService;
 
+namespace ash {
+class StickyKeysController;
+}
+
 namespace chromeos {
 namespace input_method {
 class ImeKeyboard;
@@ -51,7 +55,10 @@ class EventRewriter
     kDeviceAppleKeyboard,
   };
 
-  EventRewriter();
+  // Does not take ownership of the |sticky_keys_controller|, which may also
+  // be NULL (for testing without ash), in which case sticky key operations
+  // don't happen.
+  explicit EventRewriter(ash::StickyKeysController* sticky_keys_controller);
   virtual ~EventRewriter();
 
   // Calls DeviceAddedInternal.
@@ -98,7 +105,7 @@ class EventRewriter
 #endif
 
  private:
-  // Things that internal rewriter phases can change about an Event.
+  // Things that keyboard-related rewriter phases can change about an Event.
   struct MutableKeyState {
     int flags;
     ui::KeyboardCode key_code;
@@ -157,6 +164,9 @@ class EventRewriter
   ui::EventRewriteStatus RewriteTouchEvent(
       const ui::TouchEvent& touch_event,
       scoped_ptr<ui::Event>* rewritten_event);
+  ui::EventRewriteStatus RewriteScrollEvent(
+      const ui::ScrollEvent& scroll_event,
+      scoped_ptr<ui::Event>* rewritten_event);
 
   // Rewriter phases. These can inspect the original |event|, but operate using
   // the current |state|, which may have been modified by previous phases.
@@ -175,6 +185,10 @@ class EventRewriter
   chromeos::input_method::ImeKeyboard* ime_keyboard_for_testing_;
   const PrefService* pref_service_for_testing_;
 
+  // The sticky keys controller is not owned here;
+  // at time of writing it is a singleton in ash::Shell>
+  ash::StickyKeysController* sticky_keys_controller_;
+
   DISALLOW_COPY_AND_ASSIGN(EventRewriter);
 };