Part 2 of base::IDMap refactor to eliminate IDMapOwnPointer/IDMapExternalPointer modes

Now callers directly specify what type of pointer they want IDMap to
hold using the template parameter.

Part 1 is at https://codereview.chromium.org/2480293004/

BUG=647091

TBR=dbeam (for chrome/browser/ui/webui/options/certificate_manager_handler.cc)
TBR=jam (for all other non-base/ changes)

Review-Url: https://codereview.chromium.org/2496653002
Cr-Commit-Position: refs/heads/master@{#435539}
73 files changed