Add RenderLayerCompositor::m_rootTransformLayer

If we apply the transform at a different level in the tree, it no
no longer affects the HUD.

BUG=344295, 299837

Review URL: https://codereview.chromium.org/170153002

git-svn-id: svn://svn.chromium.org/blink/trunk@167579 bbb929c8-8fbe-4397-9dbb-9b2b20218538
RemoteDebugger fix after r167500

BUG=
R=pfeldman@chromium.org, sergeyv@chromium.org

Review URL: https://codereview.chromium.org/174843002

git-svn-id: svn://svn.chromium.org/blink/trunk@167580 bbb929c8-8fbe-4397-9dbb-9b2b20218538
StyleSheetList::document() should return null after detaching the StyleSheetList from document.

BUG=337059
TEST=fast/dom/shadow/access-document-of-detached-stylesheetlist-crash.html

Review URL: https://codereview.chromium.org/170403002

git-svn-id: svn://svn.chromium.org/blink/trunk@167581 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Add partitionAllocGetSize() for determining actual size of allocation

Since PartitionAlloc allocates from buckets of quantized sizes, it will
sometimes allocate a significantly larger block than requested.  Add the
utility function partitionAllocGetSize() for retrieving the actual size
of an allocation, useful if the client can make use of the extra size.

BUG=

Review URL: https://codereview.chromium.org/169523004

git-svn-id: svn://svn.chromium.org/blink/trunk@167582 bbb929c8-8fbe-4397-9dbb-9b2b20218538