Move StoragePartitionHttpCacheRemover to browsing_data/ components.
This enables us to use StoragePartitionHttpCacheRemover from extensions/.
SPHCRemover used to live under chrome/.
WebViewGuest, which uses it lives in extensions/, we currently have to install
a chrome/ delegate (ChromeWebViewGuestDelegate) to call into SPHCRemover.
This change will enable us to use SPHCRemover directly from WebViewGuest in
extensions/.
BUG=471287
Test=None, internal only change.
Review URL: https://codereview.chromium.org/
1049423002
Cr-Commit-Position: refs/heads/master@{#323385}