DevTools: Selecting the "Console" tab in the drawer does not focus the prompt

BUG=335529

Review URL: https://codereview.chromium.org/135303008

git-svn-id: svn://svn.chromium.org/blink/trunk@165311 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Add a UseCounter for the HTMLMediaElement.canPlayType keySystem argument

This has been replaced in the spec by MediaKeys.isTypeSupported:

https://dvcs.w3.org/hg/html-media/raw-file/tip/encrypted-media/encrypted-media.html#extensions

Add a counter now so that we have the data needed for removal when the
new spec has been implemented.

BUG=334941

Review URL: https://codereview.chromium.org/135003003

git-svn-id: svn://svn.chromium.org/blink/trunk@165312 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: use extensions for SearchScopes

Review URL: https://codereview.chromium.org/135903008

git-svn-id: svn://svn.chromium.org/blink/trunk@165313 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove BLINK_PLATFORM_EXPORT from WebWaitableEvent

It's not a class exported from blink_platform but to be
implemented by the embedder.

BUG=334263
TEST=build

Review URL: https://codereview.chromium.org/141573004

git-svn-id: svn://svn.chromium.org/blink/trunk@165314 bbb929c8-8fbe-4397-9dbb-9b2b20218538