DevTools: Fix web workers snapshots are not saved to disk

The snapshot URL was revoked too early producing a 404 error
not giving it a chance to be saved.

Also add a slash before the snapshot name to cut the blob url hash off
the snapshot file name.

BUG=254540
R=loislo@chromium.org

Review URL: https://codereview.chromium.org/18156003

git-svn-id: svn://svn.chromium.org/blink/trunk@153423 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: [Performance] Fix for heap snapshot performance tests.

The bot was offline so we missed the change were we changed the logic.

BUG=none
TEST=PerformanceTests/inspector
R=yurys@chromium.org

Review URL: https://codereview.chromium.org/18156004

git-svn-id: svn://svn.chromium.org/blink/trunk@153424 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove calls to updateMarqueePosition from RenderLayer

updateMarqueePosition only requires layout information for its
computations, which is why we can remove the 2 calls to the function
in RenderLayer:
- updateLayerPositions is called after layout so it's strictly
equivalent to calling it during layout. Also the current logic in
RenderLayer was working around <marquee> triggering spurious
invalidation (see e.g. the ASSERT fix for
https://bugs.webkit.org/show_bug.cgi?id=92464).
- the call in updateLayerPositionsAfterScroll was unneeded as
updateLayerPositions doesn't rely on the scroll offset.

The rebaselines correspond to timing difference in the tests as we
start the <marquee> during layout and not just after.

R=leviw@chromium.org

Review URL: https://codereview.chromium.org/18257002

git-svn-id: svn://svn.chromium.org/blink/trunk@153425 bbb929c8-8fbe-4397-9dbb-9b2b20218538