Remove deprecated base::Bind APIs (see issue #3140)

This CL removes the following deprecated APIs:

- base::Bind()
- base::Callback
- base::Closure
- base::CancelableCallback
- base::CancelableClosure

The behavior that these APIs provided is still available using the *Repeating*
variants. However, consider strongly whether using these variants is actually
necessary in your case or whether the *Once* variants will suffice: unless your
callback *objects* (note: not variables!) need to be called multiple times,
they most likely can and should be the Once variants.

This applies the same changes as https://crrev.com/6cc94b5339.

include/base/cef_bind.h

@@ -54,9 +54,6 @@
 //   auto cb = base::BindOnce(&C::F, instance);
 //   std::move(cb).Run();  // Identical to instance->F()
 //
-// base::Bind is currently a type alias for base::BindRepeating(). In the
-// future, we expect to flip this to default to base::BindOnce().
-//
 // See //docs/callback.md for the full documentation.
 //
 // -----------------------------------------------------------------------------
@@ -126,17 +123,6 @@ BindRepeating(Functor&& functor, Args&&... args) {
                                                std::forward<Args>(args)...);
 }
 
-// Unannotated Bind.
-// TODO(tzik): Deprecate this and migrate to OnceCallback and
-// RepeatingCallback, once they get ready.
-template <typename Functor, typename... Args>
-inline Callback<internal::MakeUnboundRunType<Functor, Args...>> Bind(
-    Functor&& functor,
-    Args&&... args) {
-  return base::BindRepeating(std::forward<Functor>(functor),
-                             std::forward<Args>(args)...);
-}
-
 // Special cases for binding to a base::Callback without extra bound arguments.
 // We CHECK() the validity of callback to guard against null pointers
 // accidentally ending up in posted tasks, causing hard-to-debug crashes.
@@ -159,12 +145,6 @@ RepeatingCallback<Signature> BindRepeating(
   return callback;
 }
 
-template <typename Signature>
-Callback<Signature> Bind(Callback<Signature> callback) {
-  CHECK(callback);
-  return callback;
-}
-
 // Unretained() allows binding a non-refcounted class, and to disable
 // refcounting on arguments that are refcounted objects.
 //