GitLab

Note: this is a reland of https://codereview.chromium.org/373153002/
after plugging a memory leak.

BookmarkStorage isn't ref counted anymore since
https://codereview.chromium.org/370323002, and the LoadCallback() task
now gets a WeakPtr to the owning BookmarkStorage. However, it gets a
raw pointer to the BookmarkLoadDetails object, which is still owned
by BookmarkStorage and may have been destroyed when the background
task runs.

This happened on iOS tests after a recent merge.

TBR=sky@chromium.org
BUG=165760

Review URL: https://codereview.chromium.org/376203002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@282097 0039d316-1c4b-4281-b951-d872f2087c98