GitLab

Converts files located in ios/web/net.

Removes property_releaser usage. Includes results of ARCMigrate run.
Replaces WeakNSObjects with __weak variables. Inserts compile guards.

Additionaly, renames ivars from trailing underscore to leading.

BUG=624365
TEST=None

Review-Url: https://codereview.chromium.org/2247303009
Cr-Commit-Position: refs/heads/master@{#414417}