Move ExtensionService::GetExtensionById() to ExtensionRegistry

This will allow app_shell to use it without an ExtensionService

BUG=none
TEST=added unit_tests ExtensionRegistryTest.GetExtensionById
R=yoz@chromium.org
TBR=pkotwicz@chromium.org for chrome/browser/themes

Review URL: https://codereview.chromium.org/125573002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@243423 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 243423
Pass through the parent_tab_id when creating a new tab.

BUG=328080
NOTRY=true

Review URL: https://codereview.chromium.org/103213015

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@243424 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 243424