[Retry] FileAPI: Add WebFileSystem::resolveURL

NOTE: There is no change from the original patch:
https://codereview.chromium.org/23537011/

This introduces WebFileSystem::resolveURL so that resolveLocalFileSystemURL,
a member of FileSystem API, can resolve a filesystem URL for external
filesystem.

This includes:
- Cracking the given filesystem URL not in Blink side but in Chromium side so
that we can get more specific external filesystem type (e.g. SyncFileSystem).
It is necessary to resolve the external filesystem URL.
- Replacing readFileSystem with resolveURL since it's used only to resolve URLs.
- Changing the error code, and these must be correct:
(http://dev.w3.org/2009/dap/file-system/file-dir-sys.html#errors-and-exceptions)

Depends on Chromium side change:
https://codereview.chromium.org/23526076/


BUG=177137
TEST=run_webkit_tests.sh http/tests/filesystem/\*
TEST=run_webkit_tests.sh http/tests/inspector/filesystem/\*
TBR=kinuko@chromium.org,tzik@chromium.org,abarth@chromium.org

Review URL: https://chromiumcodereview.appspot.com/24955002

git-svn-id: svn://svn.chromium.org/blink/trunk@158511 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Web Animations: Add AnimatableLengthSize for animating border-radius

This patch adds the AnimatableLengthSize class used by the Web Animations
implementation for animating border-radius.
It adds better support fo AnimatableNumber for generating non-negative
CSS values.

The changes to the border-radius interpolation test uncover bugs in the
existing implementation: crbug.com/289792

BUG=257591

Review URL: https://chromiumcodereview.appspot.com/23503051

git-svn-id: svn://svn.chromium.org/blink/trunk@158513 bbb929c8-8fbe-4397-9dbb-9b2b20218538