Add experimental Support for DOM3 KeyboardEvent key value

public/platform/Platform.h

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 598 matching lines @@
     // based on the value defined in ui/events/keycodes/dom4/keycode_converter_data.h.
     // Returns null string, if DOM code value is not found.
     virtual WebString domCodeStringFromEnum(int domCode) { return WebString(); }
 
     // This method converts from the suppled DOM code value to the
     // embedder's DOM code enum for the key pressed. |codeString| is defined in
     // ui/events/keycodes/dom4/keycode_converter_data.h.
     // Returns 0, if DOM code enum is not found.
     virtual int domEnumFromCodeString(const WebString& codeString) { return 0; }
 
+    // This method converts from the supplied DOM |key| enum to the
+    // corresponding DOM |key| string value for the key pressed. |domKey| values are
+    // based on the value defined in ui/events/keycodes/dom3/dom_key_data.h.
+    // Returns empty string, if DOM key value is not found.
+    virtual WebString domKeyStringFromEnum(int domKey) { return WebString(); }

[Rick Byers, 2015/04/20 19:49:46]

Since this feature is 'experimental' I assume it's fine to land (and potentially
ship) the blink side before the chromium side lands, right?  The feature will be
somewhat broken without the chromium CL, but only when pages attempt to use
strings, right?  That's probably fine, but we should aim to have the chromium
side landed in the same milestone (i.e. both blink and chromium sides need to
land before M44 branch on May 15th).  A bunch of users do run with
--enable-experimental-web-platform-features and so this could trigger bugs on
webpages that are surprised to see empty strings.

[Habib Virji, 2015/04/29 16:00:50]

Yes Rick, i will be working this week to push all the changes related to DomKey
. If successful will send a patch around May 15, to remove experimental flag.

+
+    // This method converts from the suppled DOM |key| value to the
+    // embedder's DOM |key| enum for the key pressed. |keyString| is defined in
+    // ui/events/keycodes/dom3/dom_key_data.h.
+    // Returns 0 if DOM key enum is not found.
+    virtual int domKeyEnumFromString(const WebString& keyString) { return 0; }
+
     // Quota -----------------------------------------------------------
 
     // Queries the storage partition's storage usage and quota information.
     // WebStorageQuotaCallbacks::didQueryStorageUsageAndQuota will be called
     // with the current usage and quota information for the partition. When
     // an error occurs WebStorageQuotaCallbacks::didFail is called with an
     // error code.
     virtual void queryStorageUsageAndQuota(
         const WebURL& storagePartition,
         WebStorageQuotaType,
@@ skipping 33 matching lines @@
 protected:
     BLINK_PLATFORM_EXPORT Platform();
     virtual ~Platform() { }
 
     WebThread* m_mainThread;
 };
 
 } // namespace blink
 
 #endif