[DomKey] Support Japanese (JIS) layout special keys

ui/events/keycodes/platform_key_map_win.cc

Index: ui/events/keycodes/platform_key_map_win.cc
diff --git a/ui/events/keycodes/platform_key_map_win.cc b/ui/events/keycodes/platform_key_map_win.cc
index 593e386936dd4167f21ca08105d0024186715185..da447d2cf0d6512f41d1f2c4d4afbc7fd18278a5 100644
--- a/ui/events/keycodes/platform_key_map_win.cc
+++ b/ui/events/keycodes/platform_key_map_win.cc
@@ -209,15 +209,41 @@ DomKey LanguageSpecificOemKeyboardCodeToDomKey(KeyboardCode key_code,
       default:
         return DomKey::NONE;
     }
+  } else if (primary_language == LANG_JAPANESE) {
+    switch (key_code) {
+      // VKEY_KANA isn't generated by any modern layouts but is a listed value
+      // that third-party apps might synthesize, so we handle it anyway.
+      case VKEY_KANA:
+      case VKEY_ATTN:
+        return DomKey::KANA_MODE;
+      case VKEY_KANJI:
+        return DomKey::KANJI_MODE;
+      case VKEY_OEM_ATTN:
+        return DomKey::ALPHANUMERIC;
+      case VKEY_OEM_FINISH:
+        return DomKey::KATAKANA;
+      case VKEY_OEM_COPY:
+        return DomKey::HIRAGANA;
+      case VKEY_DBE_SBCSCHAR:
+        return DomKey::HANKAKU;
+      case VKEY_DBE_DBCSCHAR:
+        return DomKey::ZENKAKU;
+      case VKEY_OEM_BACKTAB:
+        return DomKey::ROMAJI;
+      default:
+        return DomKey::NONE;
+    }
   }
-  // TODO(chongz): Handle Japanese keyboard layout keys 0xF0..0xF5, VKEY_KANA,
-  // VKEY_KANJI.
-  // https://crbug.com/612694
   return DomKey::NONE;
 }
 
 DomKey NonPrintableKeyboardCodeToDomKey(KeyboardCode key_code, HKL layout) {
-  // 1. Most |key_codes| have the same meaning regardless of |layout|.
+  // 1. Check if |key_code| has a |layout|-specific meaning.
+  const DomKey key = LanguageSpecificOemKeyboardCodeToDomKey(key_code, layout);
+  if (key != DomKey::NONE)
+    return key;
+
+  // 2. Most |key_codes| have the same meaning regardless of |layout|.
   const NonPrintableKeyEntry* result = std::lower_bound(
       std::begin(kNonPrintableKeyMap), std::end(kNonPrintableKeyMap), key_code,
       [](const NonPrintableKeyEntry& entry, KeyboardCode needle) {
@@ -225,8 +251,8 @@ DomKey NonPrintableKeyboardCodeToDomKey(KeyboardCode key_code, HKL layout) {
       });
   if (result != std::end(kNonPrintableKeyMap) && result->key_code == key_code)
     return result->dom_key;
-  // 2. Look up a |layout|-specific meaning for |key_code|.
-  return LanguageSpecificOemKeyboardCodeToDomKey(key_code, layout);
+
+  return DomKey::NONE;
 }
 
 void CleanupKeyMapTls(void* data) {
@@ -280,11 +306,12 @@ DomKey PlatformKeyMap::DomKeyFromKeyboardCodeImpl(KeyboardCode key_code,
     if (it != printable_keycode_to_key_.end()) {
       key = it->second;
       if (key != DomKey::NONE)
-        break;
+        return key;
     }
   }
 
-  return key;
+  // Return DomKey::UNIDENTIFIED to prevent US layout fall-back.
+  return DomKey::UNIDENTIFIED;
 }
 
 // static