REGRESSION(r95573): Crash when loading SVG documents in a flattened frame or any...

REGRESSION(r95573): Crash when loading SVG documents in a flattened frame or any SVG document in Chromium/Mac.
https://bugs.webkit.org/show_bug.cgi?id=68938

Source/WebCore:

Reviewed by David Hyatt.

Test: all svg tests in LayoutTests.

* rendering/RenderBlock.cpp:
(WebCore::RenderBlock::computeBlockPreferredLogicalWidths): Added a null-check for containingBlock.

Tools:

Made Chromium/Mac DRT better match how Chromium/Mac queries WebKit.

Reviewed by David Hyatt.

* DumpRenderTree/chromium/WebViewHost.cpp:
(WebViewHost::didUpdateLayout): Added width/height queries.
* DumpRenderTree/chromium/WebViewHost.h: Updated defs.

LayoutTests:

Reviewed by David Hyatt.

* fast/frames/flattening/crash-svg-document-expected.txt: Added.
* fast/frames/flattening/crash-svg-document.html: Added.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@96258 268f45cc-cd09-0410-ab3c-d52691b4dbfc