[sync] use std::multimap for BookmarkNodeMap

[sync] use std::multimap for BookmarkNodeMap

When associating bookmarks, sync nodes are matched to BookmarkNodes.
To match a BookmarkNode with a sync node, a BookmarkNodeFinder is
created and asked to find the child node with the matching title. When searching
for the title, BookmarkNodeFinder returns the first matching child in
its child_nodes_ map. This map is an unordered_map with undefined
iteration order. If sync node siblings share a title, the
BookmarkNodeFinder can erroneously swap their respective
BookmarkNodes.
To fix this, this CL makes the iteration order defined with
std::multimap, which stores pairs in insertion order.
This is safe since sync nodes are processed in the same
order as BookmarkNodes are stored.

R=skym@chromium.org
BUG=

Review-Url: https://codereview.chromium.org/2743713005
Cr-Commit-Position: refs/heads/master@{#456234}
(cherry picked from commit e4a5c1d83e0288ebe94f1d7bae7a76d8c01efffe)

Review-Url: https://codereview.chromium.org/2752523003 .
Cr-Commit-Position: refs/branch-heads/3029@{#192}
Cr-Branched-From: 939b32ee5ba05c396eef3fd992822fcca9a2e262-refs/heads/master@{#454471}
Committed: https://chromium.googlesource.com/chromium/src/+/b3eca2062fda3945fcf759a70f9eb6c10c775d82

[pavely, 2017-03-14 19:03:09]

Description was changed from

==========
[sync] use std::multimap for BookmarkNodeMap

When associating bookmarks, sync nodes are matched to BookmarkNodes.
To match a BookmarkNode with a sync node, a BookmarkNodeFinder is
created and asked to find the child node with the matching title. When searching
for the title, BookmarkNodeFinder returns the first matching child in
its child_nodes_ map. This map is an unordered_map with undefined
iteration order. If sync node siblings share a title, the
BookmarkNodeFinder can erroneously swap their respective
BookmarkNodes.
To fix this, this CL makes the iteration order defined with
std::multimap, which stores pairs in insertion order.
This is safe since sync nodes are processed in the same
order as BookmarkNodes are stored.

R=skym@chromium.org
BUG=

Review-Url: https://codereview.chromium.org/2743713005
Cr-Commit-Position: refs/heads/master@{#456234}
(cherry picked from commit e4a5c1d83e0288ebe94f1d7bae7a76d8c01efffe)
==========

to

==========
[sync] use std::multimap for BookmarkNodeMap

When associating bookmarks, sync nodes are matched to BookmarkNodes.
To match a BookmarkNode with a sync node, a BookmarkNodeFinder is
created and asked to find the child node with the matching title. When searching
for the title, BookmarkNodeFinder returns the first matching child in
its child_nodes_ map. This map is an unordered_map with undefined
iteration order. If sync node siblings share a title, the
BookmarkNodeFinder can erroneously swap their respective
BookmarkNodes.
To fix this, this CL makes the iteration order defined with
std::multimap, which stores pairs in insertion order.
This is safe since sync nodes are processed in the same
order as BookmarkNodes are stored.

R=skym@chromium.org
BUG=

Review-Url: https://codereview.chromium.org/2743713005
Cr-Commit-Position: refs/heads/master@{#456234}
(cherry picked from commit e4a5c1d83e0288ebe94f1d7bae7a76d8c01efffe)

Review-Url: https://codereview.chromium.org/2752523003 .
Cr-Commit-Position: refs/branch-heads/3029@{#192}
Cr-Branched-From:
939b32ee5ba05c396eef3fd992822fcca9a2e262-refs/heads/master@{#454471}
Committed:
https://chromium.googlesource.com/chromium/src/+/b3eca2062fda3945fcf759a70f9e...
==========

[pavely, 2017-03-14 19:03:10]

Committed patchset #1 (id:1) manually as
b3eca2062fda3945fcf759a70f9eb6c10c775d82.