Revert of Move make_scoped_ptr into //base/memory/ptr_util.h. (patchset

chromium#2 id:20001 of https://codereview.chromium.org/1838323002/ )

Reason for revert:
No longer needed given the updated migration plan.

Original issue's description:
> Move make_scoped_ptr into //base/memory/ptr_util.h.
>
> Preparatory CL for renaming scoped_ptr to std::unique_ptr. One of the
> changes is replacing all uses of make_scoped_ptr() with WrapUnique(),
> which lives in a separate header.
>
> In order to incrementally update files to use the new header, this CL
> moves make_scoped_ptr to ptr_util.h but still includes it in
> scoped_ptr.h to avoid breaking the build during the transition.
>
> BUG=554298
>
> Committed: https://crrev.com/e180e0b92e020144eb62530e561c9579cb0f35a7
> Cr-Commit-Position: refs/heads/master@{#383815}

TBR=danakj@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=554298

Review URL: https://codereview.chromium.org/1845243004 .

Cr-Commit-Position: refs/heads/master@{#384506}

base/memory/ptr_util.h

@@ -7,31 +7,6 @@
 
 #include <memory>
 
-// A function to convert T* into scoped_ptr<T>
-// Doing e.g. make_scoped_ptr(new FooBarBaz<type>(arg)) is a shorter notation
-// for scoped_ptr<FooBarBaz<type>>(new FooBarBaz<type>(arg))
-//
-// Why doesn't this just return a scoped_ptr?
-//
-// make_scoped_ptr is currently being migrated out of scoped_ptr.h, so we can
-// globally rename make_scoped_ptr to WrapUnique without breaking the build.
-// Doing so without breaking intermediate builds involves several steps:
-//
-// 1. Move make_scoped_ptr into ptr_util.h and include ptr_util.h from
-//    scoped_ptr.h.
-// 2. Add an #include for ptr_util.h to every file that references
-//    make_scoped_ptr.
-// 3. Remove ptr_util.h include from scoped_ptr.h.
-// 4. Global rewrite everything.
-//
-// Unfortunately, step 1 introduces an awkward cycle of dependencies between
-// ptr_util.h and scoped_ptr.h To break that cycle, we exploit the fact that
-// scoped_ptr is really just a type alias for std::unique_ptr.
-template <typename T>
-std::unique_ptr<T> make_scoped_ptr(T* ptr) {
-  return std::unique_ptr<T>(ptr);
-}
-
 namespace base {
 
 // Helper to transfer ownership of a raw pointer to a std::unique_ptr<T>.

base/memory/scoped_ptr.h

@@ -11,10 +11,15 @@
 
 #include <memory>
 
-// TODO(dcheng): Temporary, to facilitate transition off scoped_ptr.
-#include "base/memory/ptr_util.h"
-
 template <typename T, typename D = std::default_delete<T>>
 using scoped_ptr = std::unique_ptr<T, D>;
 
+// A function to convert T* into scoped_ptr<T>
+// Doing e.g. make_scoped_ptr(new FooBarBaz<type>(arg)) is a shorter notation
+// for scoped_ptr<FooBarBaz<type> >(new FooBarBaz<type>(arg))
+template <typename T>
+scoped_ptr<T> make_scoped_ptr(T* ptr) {
+  return scoped_ptr<T>(ptr);
+}
+
 #endif  // BASE_MEMORY_SCOPED_PTR_H_