Remove BitmapFetcher's dependency on Profile

BitmapFetcher just needs a RequestContext and not a whole profile.
This is needed by https://codereview.chromium.org/222313005/, where
we don't want to add an implicit Profile dependency to the ProfileInfoCache.

BUG=305048
TEST=Existing tests.

Review URL: https://codereview.chromium.org/253623002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@266363 0039d316-1c4b-4281-b951-d872f2087c98
6 files changed