[HTML Imports] Let script of imported document running.

This change allows <script> inside imported document running.
The implementation is based on a proposal at
https://www.w3.org/Bugs/Public/show_bug.cgi?id=22413.

This CL teaches ScriptLoader about HTML Imports so that it loads and
evaluates script if the document is an import.

For that purpose, now ScriptLoader distinguishes "executing document" which
is a master and "element" document which is an import, then executes scripts
on "executing" document.

Here are some remarks:
- This change doesn't make other resources, including stylesheets and images,
   being loaded on imports. The spec doesn't mention about them.
- This change doesn't take care of execution order. It will be attacked in
   following changes.
- Some of new CSP related tests capture some FAILures. This represents the 
   current limitation of Blink's CSP handling of HTML Import:
   It cannot prohibit eval() in imports and just follows master's context.
   This is because the imported scripts run on master's context and
   there is no way to the source of the eval() calls.

BUG=240592
TEST=csp-import-block-but-*.html, import-script-nosniff.html, import-script.html,
          import-script-prototypes.html
R=dglazkov,abarth

Review URL: https://chromiumcodereview.appspot.com/19762002

git-svn-id: svn://svn.chromium.org/blink/trunk@155149 bbb929c8-8fbe-4397-9dbb-9b2b20218538
WebCrypto: Fix an un-initialized value in the mock implementation of importKey()

BUG=245025

Review URL: https://chromiumcodereview.appspot.com/21044004

git-svn-id: svn://svn.chromium.org/blink/trunk@155150 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Initial value of @font-face's font-variant property should be 'normal'

When @font-face does not have a font-variant property, it was defaulted to
'normal,small-caps' (all supported variants). The spec says the initial
value is 'normal'.

spec: http://www.w3.org/TR/css3-fonts/#propdef-font-variant

Review URL: https://chromiumcodereview.appspot.com/21190003

git-svn-id: svn://svn.chromium.org/blink/trunk@155151 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Move WebKitUnitTests.gyp out of Source/WebKit/chromium

We're close to removing Source/WebKit/chromium, which means we need to move all
the remaining files to new homes.

R=jamesr

Review URL: https://chromiumcodereview.appspot.com/21106004

git-svn-id: svn://svn.chromium.org/blink/trunk@155152 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Style resolution: Move display property to animation pass

In r154056 a pass for applying properties which generate animations was
introduced so that animations could be started at the appropriate point.
However, starting an animation depends on the resolved value of display not
being 'none'. This patch moves the resolution of display to be a part of the
animation pass.

Covered by existing tests. No change in behavior.

BUG=232273

Review URL: https://chromiumcodereview.appspot.com/21003002

git-svn-id: svn://svn.chromium.org/blink/trunk@155153 bbb929c8-8fbe-4397-9dbb-9b2b20218538