Apply Ash's key rewriter to an aura::MouseEvent so that Modifler+Click is handled correctly

chrome/browser/ui/views/ash/key_rewriter.cc

Index: chrome/browser/ui/views/ash/key_rewriter.cc
diff --git a/chrome/browser/ui/views/ash/key_rewriter.cc b/chrome/browser/ui/views/ash/key_rewriter.cc
index 737e6099cb2fc3c5f099a817843279794d679228..6c5720fce7589a39e5f08c590c005681834708d2 100644
--- a/chrome/browser/ui/views/ash/key_rewriter.cc
+++ b/chrome/browser/ui/views/ash/key_rewriter.cc
@@ -179,14 +179,16 @@ void KeyRewriter::RewriteForTesting(aura::KeyEvent* event) {
 
 ash::KeyRewriterDelegate::Action KeyRewriter::RewriteOrFilterKeyEvent(
     aura::KeyEvent* event) {
-  const ash::KeyRewriterDelegate::Action kActionRewrite =
-      ash::KeyRewriterDelegate::ACTION_REWRITE_EVENT;
-  if (!event->HasNativeEvent()) {
-    // Do not handle a fabricated event generated by tests.
-    return kActionRewrite;
-  }
-  Rewrite(event);
-  return kActionRewrite;  // Do not drop the event.
+  if (event->HasNativeEvent())
+    Rewrite(event);
+  return ash::KeyRewriterDelegate::ACTION_REWRITE_EVENT;
+}
+
+ash::KeyRewriterDelegate::Action KeyRewriter::RewriteOrFilterLocatedEvent(
+    aura::LocatedEvent* event) {
+  if (event->HasNativeEvent())
+    RewriteLocatedEvent(event);
+  return ash::KeyRewriterDelegate::ACTION_REWRITE_EVENT;
 }
 
 void KeyRewriter::OnKeyboardMappingChanged(const aura::RootWindow* root) {
@@ -353,6 +355,54 @@ bool KeyRewriter::IsAppleKeyboard() const {
   return type == kDeviceAppleKeyboard;
 }
 
+void KeyRewriter::GetRemappedModifierMasks(
+    int original_flags,
+    unsigned int original_native_modifiers,
+    int* remapped_flags,
+    unsigned int* remapped_native_modifiers) const {
+#if defined(OS_CHROMEOS)
+  // TODO(glotov): remove the following condition when we do not restart chrome
+  // when user logs in as guest. See Rewrite() for details.
+  if (chromeos::UserManager::Get()->IsLoggedInAsGuest() &&
+      chromeos::BaseLoginDisplayHost::default_host()) {
+    return;
+  }
+
+  const PrefService* pref_service =
+      pref_service_ ? pref_service_ : GetPrefService();
+  if (!pref_service)
+    return;
+
+  for (size_t i = 0; i < arraysize(kModifierFlagToPrefName); ++i) {
+    if (original_native_modifiers &
+        kModifierFlagToPrefName[i].native_modifier) {
+      const ModifierRemapping* remapped_key =
+          GetRemappedKey(kModifierFlagToPrefName[i].pref_name, *pref_service);
+      // Rewrite Command-L/R key presses on an Apple keyboard to Control-L/R.
+      if (IsAppleKeyboard() &&
+          (kModifierFlagToPrefName[i].native_modifier == Mod4Mask)) {
+        remapped_key = kModifierRemappingCtrl;
+      }
+      if (remapped_key) {
+        *remapped_flags |= remapped_key->flag;
+        *remapped_native_modifiers |= remapped_key->native_modifier;
+      } else {
+        *remapped_flags |= kModifierFlagToPrefName[i].flag;
+        *remapped_native_modifiers |=
+            kModifierFlagToPrefName[i].native_modifier;
+      }
+    }
+  }
+
+  *remapped_flags =
+      (original_flags & ~(ui::EF_CONTROL_DOWN | ui::EF_ALT_DOWN)) |
+      *remapped_flags;
+  *remapped_native_modifiers =
+      (original_native_modifiers & ~(Mod4Mask | ControlMask | Mod1Mask)) |
+      *remapped_native_modifiers;
+#endif
+}
+
 bool KeyRewriter::RewriteModifiers(aura::KeyEvent* event) {
   // Do nothing if we have just logged in as guest but have not restarted chrome
   // process yet (so we are still on the login screen). In this situations we
@@ -381,8 +431,6 @@ bool KeyRewriter::RewriteModifiers(aura::KeyEvent* event) {
 
   ui::KeyboardCode remapped_keycode = event->key_code();
   KeyCode remapped_native_keycode = xkey->keycode;
-  int remapped_flags = 0;
-  unsigned int remapped_native_modifiers = 0U;
 
   // First, remap |keysym|.
   const char* pref_name = NULL;
@@ -420,30 +468,10 @@ bool KeyRewriter::RewriteModifiers(aura::KeyEvent* event) {
   }
 
   // Next, remap modifier bits.
-  for (size_t i = 0; i < arraysize(kModifierFlagToPrefName); ++i) {
-    if (xkey->state & kModifierFlagToPrefName[i].native_modifier) {
-      const ModifierRemapping* remapped_key =
-          GetRemappedKey(kModifierFlagToPrefName[i].pref_name, *pref_service);
-      // Rewrite Command-L/R key presses on an Apple keyboard to Control-L/R.
-      if (IsAppleKeyboard() &&
-          (kModifierFlagToPrefName[i].native_modifier == Mod4Mask)) {
-        remapped_key = kModifierRemappingCtrl;
-      }
-      if (remapped_key) {
-        remapped_flags |= remapped_key->flag;
-        remapped_native_modifiers |= remapped_key->native_modifier;
-      } else {
-        remapped_flags |= kModifierFlagToPrefName[i].flag;
-        remapped_native_modifiers |= kModifierFlagToPrefName[i].native_modifier;
-      }
-    }
-  }
-
-  remapped_flags = (event->flags() & ~(ui::EF_CONTROL_DOWN | ui::EF_ALT_DOWN)) |
-      remapped_flags;
-  remapped_native_modifiers =
-      (xkey->state & ~(Mod4Mask | ControlMask | Mod1Mask)) |
-      remapped_native_modifiers;
+  int remapped_flags = 0;
+  unsigned int remapped_native_modifiers = 0U;
+  GetRemappedModifierMasks(event->flags(), xkey->state,
+                           &remapped_flags, &remapped_native_modifiers);
 
   // Toggle Caps Lock if the remapped key is ui::VKEY_CAPITAL, but do nothing if
   // the original key is ui::VKEY_CAPITAL (i.e. a Caps Lock key on an external
@@ -595,6 +623,42 @@ bool KeyRewriter::RewriteBackspaceAndArrowKeys(aura::KeyEvent* event) {
   return rewritten;
 }
 
+void KeyRewriter::RewriteLocatedEvent(aura::LocatedEvent* event) {
+#if defined(OS_CHROMEOS)
+  XEvent* xevent = event->native_event();
+  if (!xevent || xevent->type != GenericEvent)
+    return;
+
+  XIDeviceEvent* xievent = static_cast<XIDeviceEvent*>(xevent->xcookie.data);
+  if (xievent->evtype != XI_ButtonPress && xievent->evtype != XI_ButtonRelease)
+    return;
+
+  // First, remap modifier masks.
+  int remapped_flags = 0;
+  unsigned int remapped_native_modifiers = 0U;
+  GetRemappedModifierMasks(event->flags(), xievent->mods.effective,
+                           &remapped_flags, &remapped_native_modifiers);
+  xievent->mods.effective = remapped_native_modifiers;
+
+  // Then, remap Alt+Button1 to Button3.
+  if ((xievent->mods.effective & Mod1Mask) && xievent->detail == 1) {
+    xievent->mods.effective &= ~Mod1Mask;
+    xievent->detail = 3;
+    if (xievent->evtype == XI_ButtonRelease) {
+      // On the release clear the left button from the existing state and the
+      // mods, and set the right button.
+      XISetMask(xievent->buttons.mask, 3);
+      XIClearMask(xievent->buttons.mask, 1);
+      xievent->mods.effective &= ~Button1Mask;
+    }
+  }
+
+  event->set_flags(ui::EventFlagsFromNative(xevent));
+#else
+  // TODO(yusukes): Support Ash on other platforms if needed.
+#endif
+}
+
 void KeyRewriter::OverwriteEvent(aura::KeyEvent* event,
                                  unsigned int new_native_keycode,
                                  unsigned int new_native_state,