Use relative path for scripts loaded in content WebUI's

Specifying relative path works exactly the same as specifying absolute
path, as long as the script is declared using
WebUIDataSource::AddResourcePath (which it is in case of changed
WebUIs). So there is no behavioral change in case of Chromium. The
reason for this change is it makes the live of embedders of content
easier when embedder is loading the WebUI from a scheme that is not
chrome: (it is opera: for us). It allows us to save on on adding
security policy overrides for each content WebUI.

BUG=

Review URL: https://codereview.chromium.org/26930002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230401 0039d316-1c4b-4281-b951-d872f2087c98
Use ScopedFile directly instead of scoped_ptr<ScopedFile> in Bind

After http://crrev.com/230080 user-defined move-only-type
can be passed by base::Passed() too, so we can remove some unnecessary scoped_ptr
indirection.

BUG=none

Review URL: https://codereview.chromium.org/30943003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230402 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 230401
This patch is a preparation step before landing
https://codereview.chromium.org/31093002/

It disables chromium tests that will fail as the
BeforeUnload behavior is going to be changed on the
Blink-side. These tests will be fixed and reenabled
after the blink roll.

BUG=286301
TBR=Mike West

Review URL: https://codereview.chromium.org/37163002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230403 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 230403