WebPrivatePtr: avoid creating temporary Persistent<> on assignment.

For RefCountedGarbageCollected objects wrapped in a WebPrivatePtr, the
PtrStorageImpl::assign(PassRefPtr<T>) overload potentially created a
Persistent on assigning its underlying raw pointer, even if a RawPtr<>
was passed along (due to the implicit RawPtr<T> conversion that
PassRefPtr<T> provides.)

This assign() overload serves no real purpose with Oilpan enabled;
provide a more appropriate RawPtr<T> version there.

R=haraken@chromium.org,tkent@chromium.org
BUG=357163

Review URL: https://codereview.chromium.org/313173009

git-svn-id: svn://svn.chromium.org/blink/trunk@175558 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Set correct Function.length on overloaded and variadic methods

According to WebIDL, the Function.length property should be the length of
shortest argument list in the effective overload set for argument count 0.
This means for instance that variadic arguments don't contribute to the
length.

BUG=377718

Review URL: https://codereview.chromium.org/296403007

git-svn-id: svn://svn.chromium.org/blink/trunk@175559 bbb929c8-8fbe-4397-9dbb-9b2b20218538
GC_TRACING dumps its result to stderr

Before this patch, GC_TRACING dumped its result to stdout.
This has caused all LayoutTests to fail.

This patch changes dump output to stderr, so LayoutTest run is not affected.

Unfortunately there is no trybot with ENABLE(GC_TRACING).
NOTRY=true
BUG=381038

Review URL: https://codereview.chromium.org/314943004

git-svn-id: svn://svn.chromium.org/blink/trunk@175560 bbb929c8-8fbe-4397-9dbb-9b2b20218538