CL up at https://codereview.chromium.org/2398613002

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/a067deede18317270cd2f118615650a2a755de8e

commit a067deede18317270cd2f118615650a2a755de8e
Author: jkarlin <jkarlin@chromium.org>
Date: Thu Oct 27 14:48:33 2016

[HttpCache] LOAD_ONLY_FROM_CACHE should not imply LOAD_PREFERRING_CACHE

LOAD_ONLY_FROM_CACHE won't go to the network, but it also skips the check to
see if the cache entry is valid. Some clients need to load only from cache,
but also ensure that the returned entry is valid. To accomplish this, this CL:

1) Renames LOAD_PREFERRING_CACHE -> LOAD_SKIP_CACHE_VALIDATION
2) Changes LOAD_ONLY_FROM_CACHE to check entry validity by default
3) Changes all existing uses of LOAD_ONLY_FROM_CACHE to also add
   LOAD_SKIP_CACHE_VALIDATION, keeping the old behavior

BUG= 652649 
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_site_isolation

Review-Url: https://codereview.chromium.org/2398613002
Cr-Commit-Position: refs/heads/master@{#428026}

[modify] https://crrev.com/a067deede18317270cd2f118615650a2a755de8e/android_webview/browser/renderer_host/aw_resource_dispatcher_host_delegate.cc
[modify] https://crrev.com/a067deede18317270cd2f118615650a2a755de8e/chrome/browser/safe_browsing/threat_details_cache.cc
[modify] https://crrev.com/a067deede18317270cd2f118615650a2a755de8e/components/precache/core/precache_fetcher.cc
[modify] https://crrev.com/a067deede18317270cd2f118615650a2a755de8e/components/precache/core/precache_fetcher_unittest.cc
[modify] https://crrev.com/a067deede18317270cd2f118615650a2a755de8e/content/browser/download/download_request_core.cc
[modify] https://crrev.com/a067deede18317270cd2f118615650a2a755de8e/content/browser/download/save_file_manager.cc
[modify] https://crrev.com/a067deede18317270cd2f118615650a2a755de8e/content/browser/frame_host/navigation_request.cc
[modify] https://crrev.com/a067deede18317270cd2f118615650a2a755de8e/content/browser/loader/async_revalidation_manager.cc
[modify] https://crrev.com/a067deede18317270cd2f118615650a2a755de8e/content/child/web_url_request_util.cc
[modify] https://crrev.com/a067deede18317270cd2f118615650a2a755de8e/content/renderer/render_frame_impl.cc
[modify] https://crrev.com/a067deede18317270cd2f118615650a2a755de8e/ios/net/crn_http_protocol_handler.mm
[modify] https://crrev.com/a067deede18317270cd2f118615650a2a755de8e/net/base/load_flags_list.h
[modify] https://crrev.com/a067deede18317270cd2f118615650a2a755de8e/net/http/http_cache.cc
[modify] https://crrev.com/a067deede18317270cd2f118615650a2a755de8e/net/http/http_cache_transaction.cc
[modify] https://crrev.com/a067deede18317270cd2f118615650a2a755de8e/net/http/http_cache_unittest.cc
[modify] https://crrev.com/a067deede18317270cd2f118615650a2a755de8e/net/url_request/sdch_dictionary_fetcher.cc
[modify] https://crrev.com/a067deede18317270cd2f118615650a2a755de8e/net/url_request/url_request_unittest.cc