Revert 158860 "[blink] Add TextDecorationType enum"

Broke Linux build: http://build.chromium.org/p/chromium.webkit/builders/Linux%20Tests/builds/31371/steps/compile/logs/stdio

> [blink] Add TextDecorationType enum
> 
> This patch splits off a part of TextCheckingType enum into
> TextDecorationType.
> 
> After this patch, TextCheckingType enum denotes the types of spellcheck
> that Blink can request from the browser.
> 
> The browser uses the TextDecorationType enum to indicate the types of text
> decorations that Blink needs to store in text. Some of these decorations
> are visible (spelling and grammar). Other decorations are invisible (in
> custom spellcheck dictionary).
> 
> BUG=302807
> 
> Review URL: https://codereview.chromium.org/25740003

TBR=rouslan@chromium.org

Review URL: https://codereview.chromium.org/25577007

git-svn-id: svn://svn.chromium.org/blink/trunk@158869 bbb929c8-8fbe-4397-9dbb-9b2b20218538