Remove/Refactor the calls to initNonKhronosFramework

In many samples the code would do this

    if (window.initNonKhronosFramework) {
      window.initNonKhronosFramework(true);
    }

Problems with that approach

1.  When is it needed?

    Apparently it's needed for any test run in as a WebKit layout test.
    That doesn't seem like it should be bleeding into every test.

    Solution: Move it to `WebGLTestUtils.create3DContext` and from
    `description`.

    It's now called for almost all tests automatically. A flag
    makes sure it will only be called once.

2.  What does the 'true' mean? Other places call it with 'false'.

    It turns out 'true' appearently tells WebKit's testing harness not
    to timeout the test.

    Solution: Change the 'true' calls to ` initTestingHarnessWaitUntilDone`