[webkit-reviews] review requested: [Bug 107424] Make page scale shrink FrameView in applyPageScaleInCompositor mode : [Attachment 183725] Patch

[bugzilla-daemon at webkit.org]

Alexandre Elias <aelias at chromium.org> has asked  for review:
Bug 107424: Make page scale shrink FrameView in applyPageScaleInCompositor mode
https://bugs.webkit.org/show_bug.cgi?id=107424

Attachment 183725: Patch
https://bugs.webkit.org/attachment.cgi?id=183725&action=review

------- Additional Comments from Alexandre Elias <aelias at chromium.org>
Hi, this patch improves the functionality of pageScaleFactor when the setting
applyPageScaleInCompositor is true.  This is a setting we introduced for
Chromium in http://trac.webkit.org/changeset/130321 that disables the
document-level CSS scale transform associated with pageScaleFactor and makes
frameScaleFactor() always return 1 (since that function is generally used to
cancel the effect of the scale transform).  The CSS transform has proven to be
a source of complexity and bugs for us so we prefer to have our compositor
manage scaling.  However, this setting will be even more useful if the
FrameView understands that the viewport size shrinks in response to scale and
can therefore scroll normally, thus this patch.