Revert of Remove remains of webrtc/base (patchset #7 id:120001 of https://codereview.webrtc.org/2973183002/ )
Reason for revert:
Breaks lots of downstream projects.
Original issue's description:
> Remove remains of webrtc/base
>
> All downstream code have been updated to the new location.
>
> In PRESUBMIT.py:
> * Remove webrtc/rtc_base from CPP_BLACKLIST
> * Add webrtc/rtc_base to LEGACY_API_DIRS
>
> Fix some duplicated paths in
> webrtc/modules/audio_processing/test/conversational_speech/BUILD.gn
>
> BUG=webrtc:7634
> TBR=kwiberg@webrtc.org
>
> Review-Url: https://codereview.webrtc.org/2973183002
> Cr-Commit-Position: refs/heads/master@{#18948}
> Committed:
https://chromium.googlesource.com/external/webrtc/+/9483b49bafc681a8360dff7217e7651a74dea71d
TBR=kwiberg@webrtc.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:7634
Review-Url: https://codereview.webrtc.org/2976633002
Cr-Commit-Position: refs/heads/master@{#18949}
diff --git a/webrtc/base/bind.h b/webrtc/base/bind.h
new file mode 100644
index 0000000..39d441f
--- /dev/null
+++ b/webrtc/base/bind.h
@@ -0,0 +1,69 @@
+/*
+ * Copyright 2012 The WebRTC Project Authors. All rights reserved.
+ *
+ * Use of this source code is governed by a BSD-style license
+ * that can be found in the LICENSE file in the root of the source
+ * tree. An additional intellectual property rights grant can be found
+ * in the file PATENTS. All contributing project authors may
+ * be found in the AUTHORS file in the root of the source tree.
+ */
+
+// Bind() is an overloaded function that converts method calls into function
+// objects (aka functors). The method object is captured as a scoped_refptr<> if
+// possible, and as a raw pointer otherwise. Any arguments to the method are
+// captured by value. The return value of Bind is a stateful, nullary function
+// object. Care should be taken about the lifetime of objects captured by
+// Bind(); the returned functor knows nothing about the lifetime of a non
+// ref-counted method object or any arguments passed by pointer, and calling the
+// functor with a destroyed object will surely do bad things.
+//
+// To prevent the method object from being captured as a scoped_refptr<>, you
+// can use Unretained. But this should only be done when absolutely necessary,
+// and when the caller knows the extra reference isn't needed.
+//
+// Example usage:
+// struct Foo {
+// int Test1() { return 42; }
+// int Test2() const { return 52; }
+// int Test3(int x) { return x*x; }
+// float Test4(int x, float y) { return x + y; }
+// };
+//
+// int main() {
+// Foo foo;
+// cout << rtc::Bind(&Foo::Test1, &foo)() << endl;
+// cout << rtc::Bind(&Foo::Test2, &foo)() << endl;
+// cout << rtc::Bind(&Foo::Test3, &foo, 3)() << endl;
+// cout << rtc::Bind(&Foo::Test4, &foo, 7, 8.5f)() << endl;
+// }
+//
+// Example usage of ref counted objects:
+// struct Bar {
+// int AddRef();
+// int Release();
+//
+// void Test() {}
+// void BindThis() {
+// // The functor passed to AsyncInvoke() will keep this object alive.
+// invoker.AsyncInvoke(RTC_FROM_HERE,rtc::Bind(&Bar::Test, this));
+// }
+// };
+//
+// int main() {
+// rtc::scoped_refptr<Bar> bar = new rtc::RefCountedObject<Bar>();
+// auto functor = rtc::Bind(&Bar::Test, bar);
+// bar = nullptr;
+// // The functor stores an internal scoped_refptr<Bar>, so this is safe.
+// functor();
+// }
+//
+
+#ifndef WEBRTC_BASE_BIND_H_
+#define WEBRTC_BASE_BIND_H_
+
+
+// This header is deprecated and is just left here temporarily during
+// refactoring. See https://bugs.webrtc.org/7634 for more details.
+#include "webrtc/rtc_base/bind.h"
+
+#endif // WEBRTC_BASE_BIND_H_