Add diamond-key remapping support.

chrome/browser/ui/ash/event_rewriter.cc

Index: chrome/browser/ui/ash/event_rewriter.cc
diff --git a/chrome/browser/ui/ash/event_rewriter.cc b/chrome/browser/ui/ash/event_rewriter.cc
index ad5fdec8222933b98b2b6ea4d600ac8061314596..0518320716006fe5fee2018e15a22af436d56e11 100644
--- a/chrome/browser/ui/ash/event_rewriter.cc
+++ b/chrome/browser/ui/ash/event_rewriter.cc
@@ -85,6 +85,7 @@ const struct ModifierFlagToPrefName {
   { Mod4Mask, 0, prefs::kLanguageRemapSearchKeyTo },
   { ControlMask, ui::EF_CONTROL_DOWN, prefs::kLanguageRemapControlKeyTo },
   { Mod1Mask, ui::EF_ALT_DOWN, prefs::kLanguageRemapAltKeyTo },
+  { Mod2Mask, 0, prefs::kLanguageRemapDiamondKeyTo },
 };
 
 // Gets a remapped key for |pref_name| key. For example, to find out which
@@ -122,6 +123,11 @@ bool HasChromeOSKeyboard() {
       switches::kHasChromeOSKeyboard);
 }
 
+bool HasDiamondKey() {
+  return CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kHasChromeOSDiamondKey);
+}
+
 bool IsMod3UsedByCurrentInputMethod() {
   // Since both German Neo2 XKB layout and Caps Lock depend on Mod3Mask,
   // it's not possible to make both features work. For now, we don't remap
@@ -426,7 +432,7 @@ void EventRewriter::GetRemappedModifierMasks(
       (original_flags & ~(ui::EF_CONTROL_DOWN | ui::EF_ALT_DOWN)) |
       *remapped_flags;
 
-  unsigned int native_mask = Mod4Mask | ControlMask | Mod1Mask;
+  unsigned int native_mask = Mod4Mask | ControlMask | Mod1Mask | Mod2Mask;
   if (!skip_mod3)
     native_mask |= Mod3Mask;
   *remapped_native_modifiers =
@@ -467,6 +473,19 @@ bool EventRewriter::RewriteModifiers(ui::KeyEvent* event) {
   // First, remap |keysym|.
   const ModifierRemapping* remapped_key = NULL;
   switch (keysym) {
+    // On Chrome OS, XF86XK_Launch6 (F15) with Mod2Mask is sent when Diamond
+    // key is pressed.
+    case XF86XK_Launch6:
+      // When diamond key is not available, the configuration UI for Diamond
+      // key is not shown. Therefore, ignore the kLanguageRemapDiamondKeyTo
+      // syncable pref.
+      if (HasDiamondKey())
+        remapped_key =
+            GetRemappedKey(prefs::kLanguageRemapDiamondKeyTo, *pref_service);
+      // Default behavior is Ctrl key.
+      if (!remapped_key)
+        remapped_key = kModifierRemappingCtrl;
+      break;
     // On Chrome OS, XF86XK_Launch7 (F16) with Mod3Mask is sent when Caps Lock
     // is pressed (with one exception: when IsMod3UsedByCurrentInputMethod() is
     // true, the key generates XK_ISO_Level3_Shift with Mod3Mask, not
@@ -475,11 +494,12 @@ bool EventRewriter::RewriteModifiers(ui::KeyEvent* event) {
       // When a Chrome OS keyboard is available, the configuration UI for Caps
       // Lock is not shown. Therefore, ignore the kLanguageRemapCapsLockKeyTo
       // syncable pref.
-      if (HasChromeOSKeyboard())
-        remapped_key = kModifierRemappingCapsLock;
-      else
+      if (!HasChromeOSKeyboard())
         remapped_key =
             GetRemappedKey(prefs::kLanguageRemapCapsLockKeyTo, *pref_service);
+      // Default behavior is Caps Lock key.
+      if (!remapped_key)
+        remapped_key = kModifierRemappingCapsLock;
       break;
     case XK_Super_L:
     case XK_Super_R:
@@ -489,6 +509,8 @@ bool EventRewriter::RewriteModifiers(ui::KeyEvent* event) {
       else
         remapped_key =
             GetRemappedKey(prefs::kLanguageRemapSearchKeyTo, *pref_service);
+      // Default behavior is Super key, hence don't remap the event if the pref
+      // is unavailable.
       break;
     case XK_Control_L:
     case XK_Control_R: