Add the NeedsRebaseline expectation value for TestExpectations.

This makes it more clear when people are adding lines just for the purposes
of rebaselining (e.g. [ImageOnlyFailure Failure Pass] could be a line added
for rebaselining or for a flaky test).

Also allows for creating a bot that automatically does the rebaseline once
the bots have cycled.

BUG=241364

Review URL: https://chromiumcodereview.appspot.com/18560005

git-svn-id: svn://svn.chromium.org/blink/trunk@153470 bbb929c8-8fbe-4397-9dbb-9b2b20218538
[Refactoring] Extract CachedResourceLoader::canAccess()

This moves origin-based access control decision from ScriptElement to
CachedResourceLoader. Now the flag from the CORS-setting attribute
@crossorigin is stored as an ResourceLoaderOption instead of ScriptElement::m_usesRequestControl
and the decision is made by CachedResouceLoader::canAccess() instead of ScriptElement::notifyDone().
As a result, direct dependency to ResoruceRequest from ScriptElement is also fade away.

This abstraction will be used by HTML Imports as well.

TEST=none
BUG=240592
R=abarth@chromium.org

Review URL: https://codereview.chromium.org/18497002

git-svn-id: svn://svn.chromium.org/blink/trunk@153471 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove WebTestProxy override of WebFrameClient::createMediaPlayer().

While migrating webkit/renderer/media/ to content/renderer/media/ it became apparent that overriding media player creation for layout tests violates the content API. Instead a smaller public content API is exposed for test purposes.

BUG=239826

Review URL: https://chromiumcodereview.appspot.com/18130006

git-svn-id: svn://svn.chromium.org/blink/trunk@153472 bbb929c8-8fbe-4397-9dbb-9b2b20218538
gardening: rebaselined 2 rotated-tiled-clamped tests...

... and suppressed debugger-breakpoints-not-activated-on-reload.html on win debug

TBR=crogers
BUG=

Review URL: https://codereview.chromium.org/18614002

git-svn-id: svn://svn.chromium.org/blink/trunk@153473 bbb929c8-8fbe-4397-9dbb-9b2b20218538