Revert of [KeyboardEvent] Add embedder APIs to translate between Dom |key| enum and strings

Revert of [KeyboardEvent] Add embedder APIs to translate between Dom |key| enum and strings (patchset #9 id:180001 of https://codereview.chromium.org/929053004/)

Reason for revert:
This pach is still under review and was accidentally closed.

Original issue's description:
> [KeyboardEvent] Add embedder APIs to translate between Dom |key| enum and strings
> 
> Embedder API for accessing DOM3 |key| value based on the enum value.
> 
> Sets the dom |key| enum value for each WebKeyboardEvent. Blink then uses the embedded API to translate the dom |key| enum value to a value string.
> 
> It is dependent on CL 1103263004, which sets dom |key| value in X11. 
> 
> BUG=227231
> R=piman@chromium.org, Wez

TBR=wez@chromium.org,piman@chromium.org,kpschoedel@chromium.org,dtapuska@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=227231

[Habib Virji, 2015-06-26 19:23:46]

Created Revert of [KeyboardEvent] Add embedder APIs to translate between Dom
|key| enum and strings