Working around the page load problem on Linux.

After experimenting on the bots, this admittedly silly workaround seems
to work without any negative side effects. This patch makes the main browser test and
the video quality test use the same helper to load pages, and then makes that helper load
the page twice on Linux. I tried that on the bot and it manages to load the js
correctly 100% of the time if I do that.

BUG=281268

Review URL: https://codereview.chromium.org/99333010

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@240170 0039d316-1c4b-4281-b951-d872f2087c98
Same document navigations should update post state on NavigationEntry.

It's possible the page was requested as a POST, then requested again as a GET
(or vice versa). Failing to update this state can lead to spurious form
resubmission warnings.

BUG=21245
TEST=NavigationControllerTest.LoadURL_SamePage_DifferentMethod

Review URL: https://codereview.chromium.org/101323008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@240171 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 240170
SVN changes up to revision 240171
Swap ProfileManager::GetDefaultProfileOrOffTheRecord() for ProfileManager::GetActiveUserProfileOrOffTheRecord() in ChromeNewWindowDelegate
As mentioned in http://crbug.com/327499, we should move to using the last active profile.

BUG=322682
TEST=None

Review URL: https://codereview.chromium.org/108563011

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@240172 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 240172