GitLab

Both PODFreeListArenaTest and PODArenaTest had local test classes
naemd TestClass and those collided in jumbo build. This patch
changes the colliding names to be more unique inside blink/platform.

Bug: 745732
Change-Id: I8b31e62125c0e0eb84103d91f3e28dd9decd3f5f
Reviewed-on: https://chromium-review.googlesource.com/671265Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Daniel Bratell <bratell@opera.com>
Cr-Commit-Position: refs/heads/master@{#502812}