Improve SourceBuffer exception messages.

BUG=270033

Review URL: https://codereview.chromium.org/169623006

git-svn-id: svn://svn.chromium.org/blink/trunk@167320 bbb929c8-8fbe-4397-9dbb-9b2b20218538
CSP 1.1: Revert CSSOM changes.

In r166627 and r166494, we changed CSP 1.1 to block certain CSSOM
operations if 'unsafe-eval' isn't present in a 'style-src' directive.
This seems to be incompatible with the web; it broke every site using
jQuery, GitHub, etc.

It's not clear that we can (or want to) persue this change; reverting
it for now while we chat about it again in the WG.

BUG=336413,343970

Review URL: https://codereview.chromium.org/169303003

git-svn-id: svn://svn.chromium.org/blink/trunk@167321 bbb929c8-8fbe-4397-9dbb-9b2b20218538
ShadowRoot should support adjacent rules (~ and +) and positional rules (:nth-child and :nth-of-type).

Since shadowRoot is not an element, shadow root should also have the same logic as an element has, i.e. childrenAffectedByPositionalRules, childrenAffectedByDirectAdjacentRules, and so on.

SelectorChecker should use parentElementOrShadowRoot to check siblings when positional rules or adjacent rules are given.

BUG=337573
TEST=fast/dom/shadow/sibling-rules-under-shadow-root.html

Review URL: https://codereview.chromium.org/143933003

git-svn-id: svn://svn.chromium.org/blink/trunk@167322 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Web Animations: Remove didTriggerStyleRecalc from Player::update

This patch removes the plumbing of didTriggerStyleRecalc from the
code around updating players and timed items. The flag is used to
decide if we want to unfreeze the animation clock, which normally
happens after a style recalc.

I have removed the tests for this boolean in this patch. Correctly
testing the behaviour requires a bit of set up. When we later have
an internals api to count style recalcs, we can test the behaviour
with layout tests.

For more context crrev.com/46043014 added the flag originally.

BUG=334937

Review URL: https://codereview.chromium.org/162553003

git-svn-id: svn://svn.chromium.org/blink/trunk@167323 bbb929c8-8fbe-4397-9dbb-9b2b20218538