Move bind_helpers.h contents to callback_helpers.h

Followups will change includes and remove the header.

R=dcheng@chromium.org
TBR=davidben@chromium.org,dalecurtis@chromium.org

Change-Id: Idd1de7bd21102b389676eda7cabdadf866b94903
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2521248
Auto-Submit: danakj <danakj@chromium.org>
Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Commit-Queue: Dale Curtis <dalecurtis@chromium.org>
Commit-Queue: danakj <danakj@chromium.org>
Cr-Commit-Position: refs/heads/master@{#825160}

base/bind_helpers.h

@@ -5,65 +5,6 @@
 #ifndef BASE_BIND_HELPERS_H_
 #define BASE_BIND_HELPERS_H_
 
-#include <stddef.h>
-
-#include <type_traits>
-#include <utility>
-
-#include "base/bind.h"
-#include "base/callback.h"
-#include "base/memory/weak_ptr.h"
-#include "build/build_config.h"
-
-// This defines a set of simple functions and utilities that people want when
-// using {Once,Repeating}Callback<> and Bind{Once,Repeating}().
-
-namespace base {
-
-// Creates a null callback.
-class BASE_EXPORT NullCallback {
- public:
-  template <typename R, typename... Args>
-  operator RepeatingCallback<R(Args...)>() const {
-    return RepeatingCallback<R(Args...)>();
-  }
-  template <typename R, typename... Args>
-  operator OnceCallback<R(Args...)>() const {
-    return OnceCallback<R(Args...)>();
-  }
-};
-
-// Creates a callback that does nothing when called.
-class BASE_EXPORT DoNothing {
- public:
-  template <typename... Args>
-  operator RepeatingCallback<void(Args...)>() const {
-    return Repeatedly<Args...>();
-  }
-  template <typename... Args>
-  operator OnceCallback<void(Args...)>() const {
-    return Once<Args...>();
-  }
-  // Explicit way of specifying a specific callback type when the compiler can't
-  // deduce it.
-  template <typename... Args>
-  static RepeatingCallback<void(Args...)> Repeatedly() {
-    return BindRepeating([](Args... args) {});
-  }
-  template <typename... Args>
-  static OnceCallback<void(Args...)> Once() {
-    return BindOnce([](Args... args) {});
-  }
-};
-
-// Useful for creating a Closure that will delete a pointer when invoked. Only
-// use this when necessary. In most cases MessageLoop::DeleteSoon() is a better
-// fit.
-template <typename T>
-void DeletePointer(T* obj) {
-  delete obj;
-}
-
-}  // namespace base
+#include "base/callback_helpers.h"
 
 #endif  // BASE_BIND_HELPERS_H_

base/callback_helpers.h

@@ -18,7 +18,6 @@
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/compiler_specific.h"
-#include "base/memory/ptr_util.h"
 
 namespace base {
 
@@ -137,6 +136,50 @@ class BASE_EXPORT ScopedClosureRunner {
   OnceClosure closure_;
 };
 
+// Creates a null callback.
+class BASE_EXPORT NullCallback {
+ public:
+  template <typename R, typename... Args>
+  operator RepeatingCallback<R(Args...)>() const {
+    return RepeatingCallback<R(Args...)>();
+  }
+  template <typename R, typename... Args>
+  operator OnceCallback<R(Args...)>() const {
+    return OnceCallback<R(Args...)>();
+  }
+};
+
+// Creates a callback that does nothing when called.
+class BASE_EXPORT DoNothing {
+ public:
+  template <typename... Args>
+  operator RepeatingCallback<void(Args...)>() const {
+    return Repeatedly<Args...>();
+  }
+  template <typename... Args>
+  operator OnceCallback<void(Args...)>() const {
+    return Once<Args...>();
+  }
+  // Explicit way of specifying a specific callback type when the compiler can't
+  // deduce it.
+  template <typename... Args>
+  static RepeatingCallback<void(Args...)> Repeatedly() {
+    return BindRepeating([](Args... args) {});
+  }
+  template <typename... Args>
+  static OnceCallback<void(Args...)> Once() {
+    return BindOnce([](Args... args) {});
+  }
+};
+
+// Useful for creating a Closure that will delete a pointer when invoked. Only
+// use this when necessary. In most cases MessageLoop::DeleteSoon() is a better
+// fit.
+template <typename T>
+void DeletePointer(T* obj) {
+  delete obj;
+}
+
 }  // namespace base
 
 #endif  // BASE_CALLBACK_HELPERS_H_

media/gpu/android/media_codec_video_decoder.cc

@@ -13,6 +13,7 @@
 #include "base/callback_helpers.h"
 #include "base/command_line.h"
 #include "base/logging.h"
+#include "base/memory/ptr_util.h"
 #include "base/memory/weak_ptr.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/threading/sequenced_task_runner_handle.h"

media/gpu/ipc/service/vda_video_decoder.cc

@@ -12,6 +12,7 @@
 #include "base/callback_helpers.h"
 #include "base/location.h"
 #include "base/logging.h"
+#include "base/memory/ptr_util.h"
 #include "build/build_config.h"
 #include "build/chromeos_buildflags.h"
 #include "gpu/config/gpu_driver_bug_workarounds.h"

net/url_request/url_request_http_job.cc

@@ -16,6 +16,7 @@
 #include "base/file_version_info.h"
 #include "base/location.h"
 #include "base/macros.h"
+#include "base/memory/ptr_util.h"
 #include "base/metrics/field_trial.h"
 #include "base/metrics/histogram_functions.h"
 #include "base/metrics/histogram_macros.h"