Replace uses of hash_map in //base

base::hash_map is deprecated in favor of std::unordered_map (which it is a
typedef of).

The changes to tracing required updating of callers in third_party/WebKit.

Some uses were replaced with more appropriate variants: std::map,
base::flat_map, and base::small_map.

A std::hash implementation of base::FilePath is added.

BUG=576864
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.android:android_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel

Review-Url: https://codereview.chromium.org/2830093003
Cr-Original-Commit-Position: refs/heads/master@{#467761}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 1ce49f64ab5be7af3fa0a06d9bd1f826a13a0962
1 file changed