[Chromium] Fix find in page rects for overflowing content.
https://bugs.webkit.org/show_bug.cgi?id=104924

Reviewed by Julien Chaffraix.

If a div has overflowing content, we should only normalise its
coordinates against the renderview or the containing scrollable block.

TEST=WebFrameTest.FindInPageMatchRects

* src/FindInPageCoordinates.cpp:
(WebKit::enclosingScrollableAncestor):
    Helper function to find the enclosing containing block with an overflow clip.
(WebKit::toNormalizedRect):
    Pass in the container as an argument.
(WebKit::findInPageRectFromAbsoluteRect):
    Compute the container for toNormalizedRect using enclosingScrollableAncestor.
* tests/WebFrameTest.cpp:
    Add expectations for new tests in WebFrameTest::FindInPageMatchRects and WebFrameTest::FindInPage.
* tests/data/find.html:
    Add test case for <select> element.
* tests/data/find_in_page_frame.html:
    Add test cases:
      - Result 15, 16 tests that containing <div> with style float:left and
        height:0px does not impact coordinate normalization.
      - Result 17, 18 tests that matches with absolute positioning are normalized containing
        relative positioned block, even if there is a closer parent block with overflow clip.
      - Result 19 adds a test case for <select> element.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@141252 268f45cc-cd09-0410-ab3c-d52691b4dbfc