Remove deprecated API for createAudioDevice.

Blink is calling new API createAudioDevice().
It needs to remove.

TODO(crogers): remove deprecated API as soon as WebKit calls new API.

This patch is related with https://codereview.chromium.org/201303006/

BUG=353110

Review URL: https://codereview.chromium.org/201723003

git-svn-id: svn://svn.chromium.org/blink/trunk@169410 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Include HTMLMediaElement.h only where needed

Now slightly fewer files are recompiled when touching the header.

BUG=none

Review URL: https://codereview.chromium.org/196353003

git-svn-id: svn://svn.chromium.org/blink/trunk@169411 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Replace elementHasLegalLinkAttribute() helper with virtual function

Replace elementHasLegalLinkAttribute() helper with virtual function on Element:
hasLegalLinkAttribute(). elementHasLegalLinkAttribute() was a bit complex due
to all the branching. Using a virtual function distributes the code to each
class and results in clearer code.

R=tkent, adamk

Review URL: https://codereview.chromium.org/202893002

git-svn-id: svn://svn.chromium.org/blink/trunk@169412 bbb929c8-8fbe-4397-9dbb-9b2b20218538