Add a failing test to demonstrate missing overlay scrollbars.

Reflected overlay scrollbars don't always appear if the scrollable area
is not composited. This CL adds a test that demonstrates this.

BUG=396775

Review URL: https://codereview.chromium.org/411973003

git-svn-id: svn://svn.chromium.org/blink/trunk@178836 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove null check on refNode in Range::comparePoint

It is not necessary anymore after https://codereview.chromium.org/410413002/

Review URL: https://codereview.chromium.org/412143007

git-svn-id: svn://svn.chromium.org/blink/trunk@178837 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Add explicit destructors to DOM classes containing smart pointers to incomplete types

Clang on Windows tries to declare the implicit virtual destructor of
these classes so that it can diagnose mismatched exceptions
specifications. This ends up requiring that the type of the smart
pointer be complete, which it is not. This codepath does not fire on
non-Windows platforms due to the Itanium C++ ABI key function
optimization.

It is possible to fix Clang to avoid performing semantic analysis of the
destructor when it only needs to compute the exception specification,
but it is prohibitively difficult.  http://llvm.org/PR20337

Another possible fix on the Blink side would be to make the smart
pointer type complete by including the relevant header, which has the
cost of increasing transitive header bloat. Instead, simply define the
destructor out of line. This is also a minor object file size
optimization, as now the destructor is only emitted once.

R=thakis@chromium.org
BUG=82385

Review URL: https://codereview.chromium.org/412483007

git-svn-id: svn://svn.chromium.org/blink/trunk@178838 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Add a UseCounter for HTMLElement.webkitdropzone

The unprefixed attribute is not supported yet, but knowing the usage of
the prefixed attribute is still valuable.

R=jochen@chromium.org

Review URL: https://codereview.chromium.org/415093002

git-svn-id: svn://svn.chromium.org/blink/trunk@178839 bbb929c8-8fbe-4397-9dbb-9b2b20218538
StyleSheetContents::clearResolvers should clear ScopedStyleResolvers

This is a fix for crashes in oilpan builds after landing https://codereview.chromium.org/415743005/.

StyleSheetContents::clearResolvers should clear ScopedStyleResolvers as well as normal StyleResolvers.
The original CL (r178795) that introduced ScopedStyleResolver was missing this code,
and it exposed the bug in oilpan builds when we landed r178817.

BUG=340522

Review URL: https://codereview.chromium.org/419513002

git-svn-id: svn://svn.chromium.org/blink/trunk@178840 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Revert 178833 "Revert 178804 "Fixing RecordingImageBufferSurface..."

This is a revert of the revert that turned out to be innocent.

> Revert 178804 "Fixing RecordingImageBufferSurface to stay in dis..."
> 
> This CL caused image diffs in a lot of layout tests.
> 
> http://test-results.appspot.com/dashboards/flakiness_dashboard.html#group=%40ToT%20Blink&tests=animations/additive-transform-animations.html,css3/masking/clip-path-reference-userSpaceOnUse.html,fast/multicol/cell-shrinkback.html,fast/text/zero-font-size-2.html,svg/repaint/image-with-clip-path.svg,svg/text/append-text-node-to-tspan.html,svg/text/foreignObject-text-clipping-bug.xml,svg/text/text-viewbox-rescale.html,virtual/android/fullscreen/full-screen-render-inline.html,virtual/gpu/compositedscrolling/scrollbars/basic-scrollbar.html,virtual/gpu/fast/canvas/canvas-blend-image.html,virtual/gpu/fast/canvas/canvas-blend-solid.html,virtual/regionbasedmulticol/fast/multicol/newmulticol/avoid-column-break-inside.html,virtual/softwarecompositing/color-matching/image-color-matching.html,virtual/threaded/animations/additive-transform-animations.html
> 
> > Fixing RecordingImageBufferSurface to stay in display list mode
> > 
> > This fix makes RecordingImageBufferSurface track the initial
> > stack level of the SkPicture recording canvas to avoid falsely
> > rejecting canvases from display list mode due to state present
> > on the stack
> > 
> > BUG=396800
> > TEST=RecordingImageBufferSurfaceTest platform unit tests
> > NOTRY=true
> > 
> > Review URL: https://codereview.chromium.org/412993004
> 
> TBR=junov@chromium.org
> 
> Review URL: https://codereview.chromium.org/418873002

TBR=haraken@chromium.org

Review URL: https://codereview.chromium.org/418013003

git-svn-id: svn://svn.chromium.org/blink/trunk@178841 bbb929c8-8fbe-4397-9dbb-9b2b20218538