Split the experimental app list positioning into its own flag.

This CL splits the experimental app list positioning from the
--enable-experimental-app-list flag in order to allow independent
experimentation with the app list position.

BUG=344442
TBR=pkotwicz@chromium.org

Review URL: https://codereview.chromium.org/196463002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256794 0039d316-1c4b-4281-b951-d872f2087c98
Update a policy L2 of DMP.

I found following two categories which should be changed.
There can be more categories to rewrite, but now I'm not
sure which to work.


tc-webcore-fontcache:
getCachedFontData -(r15578)-> getFontResourceData -(r163273)-> getFontData

tc-webcore-tylepropertyset:
r151009 makes MutableStylePropertySet::create
r151124 makes ImmutableStylePropertySet::create


BUG=None
NOTRY=true

Review URL: https://codereview.chromium.org/197553004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256795 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 256794
Implement ServiceWorkerVersion::RegisterStatusChangeCallback to observe status changes

- Add mock impl for DispatchActivateEvent()
- Implement RegisterStatusChangeCallback()
- Rename set_status() to SetStatus(), and let it fire status change callbacks
- Make Dispatch{Install,Activate}Event actually change the version's status
- Add default implementation for Install/Activate event to EmbeddedWorkerTestHelper for testing

BUG=285976
TEST=ServiceWorkerVersionTest.InstallAndWaitCompletion
TEST=ServiceWorkerVersionTest.ActivateAndWaitCompletion

Review URL: https://codereview.chromium.org/196573005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256796 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 256795
SVN changes up to revision 256796