ServiceWorker: Add force-refreshed page registration layout test.

Add registration test for an iframe reloaded bypassing the cache.
The registration should succeed in this case.

BUG=392405

Review URL: https://codereview.chromium.org/412733003

git-svn-id: svn://svn.chromium.org/blink/trunk@178920 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Hide isXXX() type checking methods in subclasses

Hide isXXX() type checking methods in subclasses in order to catch unnecessary
calls at compile time. For e.g., it makes no sense to call
Element::isElementNode() as it is obviously true.

This CL also takes care of removing several such unnecessary calls that were
caught at compile time.

R=eseidel@chromium.org, pdr@chromium.org

Review URL: https://codereview.chromium.org/422463002

git-svn-id: svn://svn.chromium.org/blink/trunk@178921 bbb929c8-8fbe-4397-9dbb-9b2b20218538
[WebSocket] Create Peer on the worker thread.

This CL moves the WorkerThreadableWebSocketChannel::Peer construction to
the worker thread from the main thread.
That simplifies the construction and destruction of Peer and removes
#if ENABLE(OILPAN) macros.

BUG=384238

Review URL: https://codereview.chromium.org/350763007

git-svn-id: svn://svn.chromium.org/blink/trunk@178922 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: [Console] "Show all messages" checkbox is visible only if a few targets are available

BUG=

Review URL: https://codereview.chromium.org/407723002

git-svn-id: svn://svn.chromium.org/blink/trunk@178923 bbb929c8-8fbe-4397-9dbb-9b2b20218538