Revert of Move testRunner.startSpeechInput/setValueForUser to internals (https://codereview.chromium.org/176953009/)

Reason for revert:
Broke the Android compile:
  http://build.chromium.org/p/chromium.webkit/builders/Android%20Builder%20%28dbg%29/builds/25493/steps/compile/logs/stdio

Android does not enable speech input, and the methods called are guarded behind the ENABLE_INPUT_SPEECH compile-time flag. The testing code in Internals.cpp should also be guarded with the same flag.

Original issue's description:
> Move testRunner.startSpeechInput/setValueForUser to internals
> 
> Now TestRunner is being moved from CppBoundClass to gin::Wrappable,
> where it is not appropriate to use WebElements directly. This CL moves
> some functions which treats WebElement* from testRunner to internals.
> (To be exact, this CL only copies some functions, but I'll remove those ones
> in testRunner later.)
> 
> BUG=331301
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=168495

TBR=haraken@chromium.org,hajimehoshi@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=331301

Review URL: https://codereview.chromium.org/187903004

git-svn-id: svn://svn.chromium.org/blink/trunk@168498 bbb929c8-8fbe-4397-9dbb-9b2b20218538