LayoutTests:

LayoutTests:

        Reviewed by Eric.

        - test for <rdar://problem/4683948> REGRESSION: Assertion failure in [FrameProgressEntry addChild:forDataSource:] (fandango.com)

        (I both added a WebKit assertion that would fail under this test, and then did a fix to make it not fire)

        * fast/loader/start-load-in-unload-expected.txt: Added.
        * fast/loader/start-load-in-unload.html: Added.

WebKit:

        Reviewed by Eric.

        <rdar://problem/4683948> REGRESSION: Assertion failure in [FrameProgressEntry addChild:forDataSource:] (fandango.com)

        * Loader/WebFrameLoader.m:
        (-[WebFrameLoader addSubresourceLoader:]): Add a WebKit-level assertion that should fire when this bad
        situation occurs.
        * Loader/WebSubresourceLoader.m:
        (+[WebSubresourceLoader startLoadingResource:withRequest:customHeaders:referrer:forFrameLoader:]): Prevent
        the situation from occuring.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@15982 268f45cc-cd09-0410-ab3c-d52691b4dbfc