[Chromium] Correct auto-zoom when using compositor scaling
https://bugs.webkit.org/show_bug.cgi?id=107592

Reviewed by Adam Barth.

1. The scale of auto-zoom should exclude deviceScaleFactor because the compositor will handle the scaling;
2. Scroll location needs to be calculated differently when pageScaleFactor is handled by the compositor.

* src/WebViewImpl.cpp:
(WebKit::WebViewImpl::computeScaleAndScrollForHitRect):
* tests/WebFrameTest.cpp: Updated tests DivAutoZoomParamsTest, DivAutoZoomMultipleDivsTest, DivAutoZoomScaleBoundsTest and DivAutoZoomScaleFontScaleFactorTest, to make two versions of them (WebKitScaling and CompositorScaling).


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@140994 268f45cc-cd09-0410-ab3c-d52691b4dbfc