[FastTextAutosizer] Cleanup FastTextAutosizer::enabled() checks.

This patch is a followup to [1] to check enabled() on all public
functions of FastTextAutosizer. In [1] I lost an enabled() check by
mistake so I have put it back (in LayoutScope) and added asserts in
beginLayout/endLayout. I've also filed crbug.com/342260 to reduce the
number of calls to enabled().

No change in behavior as this was only observable while hacking.

[1] https://src.chromium.org/viewvc/blink?view=rev&revision=166602

BUG=342252

Review URL: https://codereview.chromium.org/158463004

git-svn-id: svn://svn.chromium.org/blink/trunk@166850 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Improve RTCIceCandidate exception messages.

Added a more helpful exception message when no candidate string
is provided to the RTCIceCandidate constructor, and adjusts the layout
test accordingly.

Also corrected one test case which contained a syntax error to instead
exercise the constructor.

BUG=270033

Review URL: https://codereview.chromium.org/156593003

git-svn-id: svn://svn.chromium.org/blink/trunk@166851 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Add mikhail.pozdnyakov to wtf WATCHLISTS

Add mikhail.pozdnyakov to wtf WATCHLISTS

BUG=none
NOTRY=true

Review URL: https://codereview.chromium.org/158963003

git-svn-id: svn://svn.chromium.org/blink/trunk@166852 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: Simplify source frame commit editing code flow

R=pfeldman

Review URL: https://codereview.chromium.org/153293003

git-svn-id: svn://svn.chromium.org/blink/trunk@166853 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Move all popup-related code in Source/web to the blink namespace

The majority of the work here was to disentangle ChromeClient from
these code paths: ChromeClient was being called from PopupContainer to
communicate with WebViewImpl. But PopupContainer is in Source/web, so
I've changed it to talk directly to WebViewImpl without going through
core. This avoids forward-declaring PopupContainer in ChromeClient.h.

Also did a bit of minor cleanup/dead code removal. Further cleanups
will happen later (e.g., handling the always-false second argument to
PopupContainer::popupOpened()).

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/154063004

git-svn-id: svn://svn.chromium.org/blink/trunk@166854 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Multi-col and column-spanning elements create new block formatting contexts

Multi-col and column-span elements create new block formatting contexts
so their margins should not collapse together if they are self-collapsing blocks.

http://www.w3.org/TR/css3-multicol/#the-multi-column-model: "A multi-column element establishes a new block formatting context, as per CSS 2.1 section 9.4.1."

http://www.w3.org/TR/css3-multicol/#column-span: "
The element establishes a new block formatting context."

BUG=

Review URL: https://codereview.chromium.org/147643002

git-svn-id: svn://svn.chromium.org/blink/trunk@166855 bbb929c8-8fbe-4397-9dbb-9b2b20218538