Change cc files from namespace WebCore to cc

Change cc files from namespace WebCore to cc

These files no longer are part of WebCore, so it doesn't make any sense to keep
that namespace.

Due to being unable to forward declare typedefs in C++, the stubs files (like
FloatSize) now define cc::FloatSize as being derived from WebCore::FloatSize.
With enough constructors, this lets them be used interchangably in the short
term until those geometry classes become real and not dependent on WebCore
files. This allows (nearly) all the forward declarations and uses of these
types in cc stay as-is with minimal churn.

BUG=none

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=156905

[jamesr, 2012-09-14 21:04:04]

lgtm

We are crazy inconsistent with our end-of-namespace comments.  Some say "//
namespace cc", some say "// cc", some don't have any comment.  This patch
doesn't make them any worse but it might be worth addressing later if the
chromium linter is smart enough to complain about it.