GTTF: Create a TestLauncher class to keep state.

This is now almost 100% just moving code around.

After that, my plan is to expose that class publicly and convert
calls of LaunchTests to use TestLauncher class instead.

Then TestResultsTracker is going to become a pure-data class,
just keeping track of the results and printing them. No running of callbacks,
no quitting the message loop. TestLauncher is going to handle that.

Furthermore, TestLauncher is going to handle test retries, which will
require more state and coordination with TestLauncherDelegate.

BUG=236893
R=sky@chromium.org

Review URL: https://codereview.chromium.org/26119003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@228946 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 228946
Move the setup of the build system into the builder class. This is so the perf try bot script can just create a BisectPerformanceMetrics instance and start building/testing without any extra setup.

BUG=
NOTRY=true

Review URL: https://codereview.chromium.org/26883008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@228947 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 228947
Made Pixel tests functional. Captures tab content and compares to ref image

BUG=278398
R=dtu@chromium.org, kbr@chromium.org, piman@chromium.org

Review URL: https://codereview.chromium.org/23478021

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@228950 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 228950