Fix r241318.

SiteInstance::GetProcess() will create a process and we don't want that. Also
added a comment.

BUG=325378

Review URL: https://codereview.chromium.org/99633004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@241557 0039d316-1c4b-4281-b951-d872f2087c98
[Telemetry]: Add V8.MemoryHeapSampleMaximumCommitted to memory metric.

BUG=None

Review URL: https://codereview.chromium.org/99863006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@241558 0039d316-1c4b-4281-b951-d872f2087c98
SessionStorageDatabase: handle inconsistent and failed databases gracefully.

BUG=328144

Review URL: https://codereview.chromium.org/100623010

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@241559 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 241558
SVN changes up to revision 241559