Retry idempotent methods on Chrome-Proxy: bypass

Requests using all idempotent HTTP methods (See RFC 2616) should be
retried after receiving a bypass message from the data reduction
proxy. Before this CL, only GET was being retried.

BUG=327740

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=241714

Review URL: https://codereview.chromium.org/99283006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@241927 0039d316-1c4b-4281-b951-d872f2087c98
[Cocoa] Change minimum window size back to 400x272.

This is a revert of crrev.com/222315. With decent device emulation
original reason (crbug.com/275686) is not relevant anymore.

BUG=329783

Review URL: https://codereview.chromium.org/106793008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@241928 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 241928