GitLab

SSLClientSessionCache::DumpMemoryStats() creates one
MemoryAllocatorDump for each cache entry. To make the memory dump lighter,
this CL dumps the total size and count and does not create sub dumps.

BUG=669108

Review-Url: https://codereview.chromium.org/2574513002
Cr-Commit-Position: refs/heads/master@{#437981}