Re-attach plugin renderers in the standard way.

When embedded content changes its source or type, it potential needs to
change its renderer. That was done by reattaching the renderer using a
combination of SubtreeStyleChange plus an explicit reattach in a custom
willRecalcStyle callback. This CL uses a standard lazy reattach instead.

Three svg tests changed their expected repaint rectangles due to the
following reason:

The reattach in willRecalcStyle did not re-attach any whitespace siblings
like the standard reattach does (certainly wrong, but I don't know if it
actually is observable as a display property change is necessary to affect
the whitespace renderers afaik). Moving to standard reattach makes
reattachment of a whitespace sibling do paint invalidation for the closest
block ancestor.

It's possible that we can improve whitespace re-attachment by:

1. Not invalidate block containers for whitespace renderers (will they ever
   render anything?)

2. Detect if we need to reattach whitespace siblings before we do the actual
   reattachment.

R=esprehn@chromim.org,leviw@chromium.org

Review URL: https://codereview.chromium.org/596773002

git-svn-id: svn://svn.chromium.org/blink/trunk@182868 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Mark SimpleShaper members fields as private

Mark all the member fields in SimpleShaper as private.

BUG=418570
R=dglazkov@chromium.org

Review URL: https://codereview.chromium.org/612173002

git-svn-id: svn://svn.chromium.org/blink/trunk@182869 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Throw errors when changing channelCount and channelCountMode for ScriptProcessors

The channelCount and channelCountMode for a ScriptProcessor node
cannot be changed after creation.  Thus, throw errors if the
the user tries to change channelCount to a different value or tries to
change channelCountMode to something other than 'explicit'.

Also fixes a bug that creation of a ScriptProcessor did not set
channelCount to the number of input channels and the channelCountMode
to 'explicit'.

See https://github.com/WebAudio/web-audio-api/issues/357

Tests added.
BUG=418224

Review URL: https://codereview.chromium.org/605403002

git-svn-id: svn://svn.chromium.org/blink/trunk@182870 bbb929c8-8fbe-4397-9dbb-9b2b20218538