2nd try of "Use the caret bounds as a fallback when GetCompositionCharacterBounds is not available"

This is a second try of r240602, which was once reverted due to a test failure in RemoteInputMethodWinTest.
This CL addresses the test failure of as well as adding a new test for the original change of r240602.

BUG=328237
TEST=ui_unittests.exe --gtest_filter=RemoteInputMethodWinTest.*

Review URL: https://codereview.chromium.org/98503007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@241149 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 241149
Support 401s in HttpAuthHandlerSpdyProxy

- Removed the test for HttpAuth::AUTH_PROXY in Factory::CreateAuthHandler.
- Removed the unit test that tests that AUTH_SERVER isn't supported.
- Added test coverage for AUTH_SERVER challenges.
- Cleaned up some tests to better reflect the usual (https + http) origin configuration.

BUG=328125

Review URL: https://codereview.chromium.org/114483002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@241150 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 241150