Build dynamic iOS SDK.

- Places most ObjC code into webrtc/sdk/objc instead.
- New gyp targets to build, strip and export symbols for dylib.
- Removes old script used to generate dylib.

BUG=

Review URL: https://codereview.webrtc.org/1903663002

Cr-Commit-Position: refs/heads/master@{#12524}
diff --git a/webrtc/sdk/objc/Framework/Classes/avfoundationvideocapturer.h b/webrtc/sdk/objc/Framework/Classes/avfoundationvideocapturer.h
new file mode 100644
index 0000000..5a70238
--- /dev/null
+++ b/webrtc/sdk/objc/Framework/Classes/avfoundationvideocapturer.h
@@ -0,0 +1,73 @@
+/*
+ *  Copyright 2015 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.
+ */
+
+#ifndef WEBRTC_API_OBJC_AVFOUNDATION_VIDEO_CAPTURER_H_
+#define WEBRTC_API_OBJC_AVFOUNDATION_VIDEO_CAPTURER_H_
+
+#import <AVFoundation/AVFoundation.h>
+
+#include "webrtc/base/scoped_ptr.h"
+#include "webrtc/media/base/videocapturer.h"
+#include "webrtc/video_frame.h"
+
+@class RTCAVFoundationVideoCapturerInternal;
+
+namespace rtc {
+class Thread;
+}  // namespace rtc
+
+namespace webrtc {
+
+class AVFoundationVideoCapturer : public cricket::VideoCapturer,
+                                  public rtc::MessageHandler {
+ public:
+  AVFoundationVideoCapturer();
+  ~AVFoundationVideoCapturer();
+
+  cricket::CaptureState Start(const cricket::VideoFormat& format) override;
+  void Stop() override;
+  bool IsRunning() override;
+  bool IsScreencast() const override {
+    return false;
+  }
+  bool GetPreferredFourccs(std::vector<uint32_t> *fourccs) override {
+    fourccs->push_back(cricket::FOURCC_NV12);
+    return true;
+  }
+
+  // Returns the active capture session. Calls to the capture session should
+  // occur on the RTCDispatcherTypeCaptureSession queue in RTCDispatcher.
+  AVCaptureSession* GetCaptureSession();
+
+  // Returns whether the rear-facing camera can be used.
+  // e.g. It can't be used because it doesn't exist.
+  bool CanUseBackCamera() const;
+
+  // Switches the camera being used (either front or back).
+  void SetUseBackCamera(bool useBackCamera);
+  bool GetUseBackCamera() const;
+
+  // Converts the sample buffer into a cricket::CapturedFrame and signals the
+  // frame for capture.
+  void CaptureSampleBuffer(CMSampleBufferRef sampleBuffer);
+
+  // Handles messages from posts.
+  void OnMessage(rtc::Message *msg) override;
+
+ private:
+  void OnFrameMessage(CVImageBufferRef image_buffer, int64_t capture_time);
+
+  RTCAVFoundationVideoCapturerInternal *_capturer;
+  rtc::Thread *_startThread;  // Set in Start(), unset in Stop().
+};  // AVFoundationVideoCapturer
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_API_OBJC_AVFOUNDATION_VIDEO_CAPTURER_H_