Use pauseAnimation instead of suspendAnimations during layout tests

The suspendAnimations path involves a converting a time offset to a 
wall clock time, followed by a conversion to monotonic time in
GraphicsLayer::suspendAnimations. This not only introduces flake but
is also incorrect when cc/ is using high-res monotonic time on Windows.
The pauseAnimation path just sends a time offset to cc.

BUG=312060

Review URL: https://codereview.chromium.org/48953002

git-svn-id: svn://svn.chromium.org/blink/trunk@160861 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Have static functions in Document.cpp take a reference in argument when possible

Have static functions in Document.cpp take a reference in argument when possible
(i.e. when the argument pointer is expected to be non-null).

R=adamk

Review URL: https://codereview.chromium.org/50763006

git-svn-id: svn://svn.chromium.org/blink/trunk@160862 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Move HashTools.h to core/css

BUG=297477

Review URL: https://codereview.chromium.org/51073002

git-svn-id: svn://svn.chromium.org/blink/trunk@160863 bbb929c8-8fbe-4397-9dbb-9b2b20218538
AppendNodeCommand should not call confusingAndOftenMisusedAttached()

This code wanted to check inActiveDocument().

Review URL: https://codereview.chromium.org/51133002

git-svn-id: svn://svn.chromium.org/blink/trunk@160864 bbb929c8-8fbe-4397-9dbb-9b2b20218538
RemoveNodeCommand shouldn't use confusingAndOftenMisusedAttached()

This code wants inActiveDocument().

Review URL: https://codereview.chromium.org/51193002

git-svn-id: svn://svn.chromium.org/blink/trunk@160865 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Implementation of script hashes for CSP.

BUG=277905

Review URL: https://codereview.chromium.org/26481005

git-svn-id: svn://svn.chromium.org/blink/trunk@160866 bbb929c8-8fbe-4397-9dbb-9b2b20218538
InsertNodeBeforeCommand shouldn't use confusingAndOftenMisusedAttached()

This code wants inActiveDocument().

Review URL: https://codereview.chromium.org/50563005

git-svn-id: svn://svn.chromium.org/blink/trunk@160867 bbb929c8-8fbe-4397-9dbb-9b2b20218538