Rename variables in ReplaceSelectionCommand::doApply to improve readability

This patch renames variables |insertionBlock| and |startBlock| in
ReplaceSelectionCommand::doApply to |enclosingBlockOfInsertionPos| and
|enclosingBlockOfVisibleStart| to improve readability.

This patch is preparation of http://crrev.com/352943002

BUG=n/a
TEST=n/a; no behavior changes

Review URL: https://codereview.chromium.org/370573004

git-svn-id: svn://svn.chromium.org/blink/trunk@177507 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Oilpan: Mark ContainerNode::ChildrenChange STACK_ALLOCATED.

And make Node* Member<>.

BUG=357163

Review URL: https://codereview.chromium.org/363383005

git-svn-id: svn://svn.chromium.org/blink/trunk@177508 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Merge the fullscreen event queues

The two queues are both processed by a single timer, so they might just
as well be a single queue, which also avoids looping over each queue
separately.

Instead of queuing Nodes, Events are created and queued. This means that
the event type is made explicit, which will make it simpler to support
both prefixed and unprefixed events using the same code.

BUG=383813

Review URL: https://codereview.chromium.org/365903006

git-svn-id: svn://svn.chromium.org/blink/trunk@177509 bbb929c8-8fbe-4397-9dbb-9b2b20218538