Suppress all the leaks from ExtensionPrefStoreTest
Suppress all the leaks from ExtensionPrefStoreTest

TBR=pam

BUG=48980
TEST=Green heapcheck bot

Review URL: http://codereview.chromium.org/2913011

git-svn-id: http://src.chromium.org/svn/trunk/src@52243 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 157d553d3e0303df795e60203b30e02f9675ce89
meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser