Revert 97465 - Revert 97446 - Modifying prefetch to account for multi-profile.

Revert 97465 - Revert 97446 - Modifying prefetch to account for multi-profile.

Items of note:
- predictor_api is gone. Most functions in predictor_api.cc have moved into the chrome_browser_net::Predictor class or the Profile class.
- The predictor state is cleaned up in the Profile dtor.
- Predictor is owned by the ProfileIOData of the profile.
- InitialObserver class is gone since each profile keeps their own info, the non-OTR don't care if anyone is OTR.
- Predictor is created by the profile and then passed to the ProfileIOData. Then its initialization is finished on the IOThread.
- ConnectInterceptor now subclasses off of UrlRequestJobFactory::Interceptor.
- Updated Profile to create a SimpleShutdownPredictor with limited functionality when in unittests.

BUG=89937
TEST=passes existing

Review URL: http://codereview.chromium.org/7467012

TBR=rlp@chromium.org
Review URL: http://codereview.chromium.org/7690006

TBR=avi@chromium.org
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=97466