Add experimental Support for DOM3 KeyboardEvent key value

public/platform/Platform.h

Index: public/platform/Platform.h
diff --git a/public/platform/Platform.h b/public/platform/Platform.h
index 562aa1cc9017ff92c597bc1b64e3888c913f8974..190f70ed0c91283328d866c7f11dd79e93807b75 100644
--- a/public/platform/Platform.h
+++ b/public/platform/Platform.h
@@ -616,6 +616,18 @@ public:
     // 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.