[CacheStorage] Give cache directories unique names

[CacheStorage] Give cache directories unique names

The CacheStorage class creates a directory for each cache based off of
a hash of the cache's name. This is problematic in situations where a
cache is deleted and then recreated (but not yet wiped from
disk as javascript might be referencing it).

This CL gives every new cache a unique directory and stores the directory
mapping in the cache storage index protobuf. Legacy caches are moved to
new directories on CacheStorage initialization.

BUG=542668
TBR=jochen, jsbell

There are two CLs in this merge as the second fixes a bug in the first.

Review URL: https://codereview.chromium.org/1414033002
Review URL: https://codereview.chromium.org/1428463002

Cr-Commit-Position: refs/heads/master@{#356055}
(cherry picked from commit 4519a22b4c1683f1e79543a4238bc5cdb1880b5e)
Cr-Commit-Position: refs/heads/master@{#356107}
(cherry picked from commit b65cfea2a48ce74ac98e2b10006e9d8b868d4553)

Committed: https://chromium.googlesource.com/chromium/src/+/26e40aa877846f7208e63860728fff703c40a122

[jkarlin, 2015-11-02 13:58:04]

Description was changed from

==========
[CacheStorage] Give cache directories unique names

The CacheStorage class creates a directory for each cache based off of
a hash of the cache's name. This is problematic in situations where a
cache is deleted and then recreated (but not yet wiped from
disk as javascript might be referencing it).

This CL gives every new cache a unique directory and stores the directory
mapping in the cache storage index protobuf. Legacy caches are moved to
new directories on CacheStorage initialization.

BUG=542668

There are two CLs in this merge as the second fixes a bug in the first.

Review URL: https://codereview.chromium.org/1414033002
Review URL: https://codereview.chromium.org/1428463002

Cr-Commit-Position: refs/heads/master@{#356055}
(cherry picked from commit 4519a22b4c1683f1e79543a4238bc5cdb1880b5e)
Cr-Commit-Position: refs/heads/master@{#356107}
(cherry picked from commit b65cfea2a48ce74ac98e2b10006e9d8b868d4553)
==========

to

==========
[CacheStorage] Give cache directories unique names

The CacheStorage class creates a directory for each cache based off of
a hash of the cache's name. This is problematic in situations where a
cache is deleted and then recreated (but not yet wiped from
disk as javascript might be referencing it).

This CL gives every new cache a unique directory and stores the directory
mapping in the cache storage index protobuf. Legacy caches are moved to
new directories on CacheStorage initialization.

BUG=542668
TBR=jochen, jsbell

There are two CLs in this merge as the second fixes a bug in the first.

Review URL: https://codereview.chromium.org/1414033002
Review URL: https://codereview.chromium.org/1428463002

Cr-Commit-Position: refs/heads/master@{#356055}
(cherry picked from commit 4519a22b4c1683f1e79543a4238bc5cdb1880b5e)
Cr-Commit-Position: refs/heads/master@{#356107}
(cherry picked from commit b65cfea2a48ce74ac98e2b10006e9d8b868d4553)
==========

[jkarlin, 2015-11-02 14:00:25]

Committed patchset #1 (id:1) manually as
26e40aa877846f7208e63860728fff703c40a122 (presubmit successful).