Taking over the bug since I am re-designing the cache and moving it into V4GetHashProtocolManager.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/1d2b239717bd198bd42f11e468e1eaca6b94cdc1

commit 1d2b239717bd198bd42f11e468e1eaca6b94cdc1
Author: vakh <vakh@chromium.org>
Date: Tue Sep 13 18:23:51 2016

Move the logic to cache the full hash responses from the server into v4_get_hash_protocol_manager.

Design doc: https://goto.google.com/design-doc-v4-full-hash-manager

Overall, this CL does the following:
1. Moves caching to V4GetHashProtocolManager.
2. Refactors V4GetHashProtocolManager to use the data structures used in rest of
the V4 code.
3. Re-defines how cache is implemented.

TODOs:
1. Done: Merge the response from the server and the response from the cache.
2. Figure out what UMA metrics to add (I have removed some that are no longer
valid after the refactor).

BUG= 616647 ,  543161 

Review-Url: https://codereview.chromium.org/2233103002
Cr-Commit-Position: refs/heads/master@{#418303}

[modify] https://crrev.com/1d2b239717bd198bd42f11e468e1eaca6b94cdc1/components/safe_browsing_db/BUILD.gn
[modify] https://crrev.com/1d2b239717bd198bd42f11e468e1eaca6b94cdc1/components/safe_browsing_db/database_manager.cc
[modify] https://crrev.com/1d2b239717bd198bd42f11e468e1eaca6b94cdc1/components/safe_browsing_db/database_manager.h
[modify] https://crrev.com/1d2b239717bd198bd42f11e468e1eaca6b94cdc1/components/safe_browsing_db/database_manager_unittest.cc
[modify] https://crrev.com/1d2b239717bd198bd42f11e468e1eaca6b94cdc1/components/safe_browsing_db/testing_util.h
[modify] https://crrev.com/1d2b239717bd198bd42f11e468e1eaca6b94cdc1/components/safe_browsing_db/util.cc
[modify] https://crrev.com/1d2b239717bd198bd42f11e468e1eaca6b94cdc1/components/safe_browsing_db/util.h
[modify] https://crrev.com/1d2b239717bd198bd42f11e468e1eaca6b94cdc1/components/safe_browsing_db/v4_database.cc
[modify] https://crrev.com/1d2b239717bd198bd42f11e468e1eaca6b94cdc1/components/safe_browsing_db/v4_database.h
[modify] https://crrev.com/1d2b239717bd198bd42f11e468e1eaca6b94cdc1/components/safe_browsing_db/v4_database_unittest.cc
[modify] https://crrev.com/1d2b239717bd198bd42f11e468e1eaca6b94cdc1/components/safe_browsing_db/v4_get_hash_protocol_manager.cc
[modify] https://crrev.com/1d2b239717bd198bd42f11e468e1eaca6b94cdc1/components/safe_browsing_db/v4_get_hash_protocol_manager.h
[modify] https://crrev.com/1d2b239717bd198bd42f11e468e1eaca6b94cdc1/components/safe_browsing_db/v4_get_hash_protocol_manager_unittest.cc
[modify] https://crrev.com/1d2b239717bd198bd42f11e468e1eaca6b94cdc1/components/safe_browsing_db/v4_local_database_manager.cc
[modify] https://crrev.com/1d2b239717bd198bd42f11e468e1eaca6b94cdc1/components/safe_browsing_db/v4_local_database_manager.h
[modify] https://crrev.com/1d2b239717bd198bd42f11e468e1eaca6b94cdc1/components/safe_browsing_db/v4_local_database_manager_unittest.cc
[modify] https://crrev.com/1d2b239717bd198bd42f11e468e1eaca6b94cdc1/components/safe_browsing_db/v4_protocol_manager_util.cc
[modify] https://crrev.com/1d2b239717bd198bd42f11e468e1eaca6b94cdc1/components/safe_browsing_db/v4_protocol_manager_util.h
[modify] https://crrev.com/1d2b239717bd198bd42f11e468e1eaca6b94cdc1/components/safe_browsing_db/v4_store.cc
[modify] https://crrev.com/1d2b239717bd198bd42f11e468e1eaca6b94cdc1/components/safe_browsing_db/v4_store.h
[modify] https://crrev.com/1d2b239717bd198bd42f11e468e1eaca6b94cdc1/tools/metrics/histograms/histograms.xml