modules/video_processing: refactor interface->include + more.

Moved/renamed:
webrtc/modules/video_processing/main/interface -> webrtc/modules/video_processing/include
webrtc/modules/video_processing/main/source/* -> webrtc/modules/video_processing
webrtc/modules/video_processing/main/test/unit_test -> webrtc/modules/video_processing/test

No downstream code seems to use this module.

BUG=webrtc:5095
TESTED=git cl try -c --bot=android_compile_rel --bot=linux_compile_rel --bot=win_compile_rel --bot=mac_compile_rel --bot=ios_rel --bot=linux_gn_rel --bot=win_x64_gn_rel --bot=mac_x64_gn_rel --bot=android_gn_rel -m tryserver.webrtc
R=pbos@webrtc.org, stefan@webrtc.org

Review URL: https://codereview.webrtc.org/1410663004 .

Cr-Commit-Position: refs/heads/master@{#10697}
diff --git a/webrtc/modules/video_processing/frame_preprocessor.h b/webrtc/modules/video_processing/frame_preprocessor.h
new file mode 100644
index 0000000..c5313b4
--- /dev/null
+++ b/webrtc/modules/video_processing/frame_preprocessor.h
@@ -0,0 +1,79 @@
+/*
+ *  Copyright (c) 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.
+ */
+
+/*
+ * frame_preprocessor.h
+ */
+#ifndef WEBRTC_MODULES_VIDEO_PROCESSING_FRAME_PREPROCESSOR_H_
+#define WEBRTC_MODULES_VIDEO_PROCESSING_FRAME_PREPROCESSOR_H_
+
+#include "webrtc/modules/video_processing/include/video_processing.h"
+#include "webrtc/modules/video_processing/content_analysis.h"
+#include "webrtc/modules/video_processing/spatial_resampler.h"
+#include "webrtc/modules/video_processing/video_decimator.h"
+#include "webrtc/typedefs.h"
+
+namespace webrtc {
+
+class VPMFramePreprocessor {
+ public:
+  VPMFramePreprocessor();
+  ~VPMFramePreprocessor();
+
+  void Reset();
+
+  // Enable temporal decimation.
+  void EnableTemporalDecimation(bool enable);
+
+  void SetInputFrameResampleMode(VideoFrameResampling resampling_mode);
+
+  // Enable content analysis.
+  void EnableContentAnalysis(bool enable);
+
+  // Set target resolution: frame rate and dimension.
+  int32_t SetTargetResolution(uint32_t width, uint32_t height,
+                              uint32_t frame_rate);
+
+  // Set target frame rate.
+  void SetTargetFramerate(int frame_rate);
+
+  // Update incoming frame rate/dimension.
+  void UpdateIncomingframe_rate();
+
+  int32_t updateIncomingFrameSize(uint32_t width, uint32_t height);
+
+  // Set decimated values: frame rate/dimension.
+  uint32_t Decimatedframe_rate();
+  uint32_t DecimatedWidth() const;
+  uint32_t DecimatedHeight() const;
+
+  // Preprocess output:
+  int32_t PreprocessFrame(const VideoFrame& frame,
+                          VideoFrame** processed_frame);
+  VideoContentMetrics* ContentMetrics() const;
+
+ private:
+  // The content does not change so much every frame, so to reduce complexity
+  // we can compute new content metrics every |kSkipFrameCA| frames.
+  enum { kSkipFrameCA = 2 };
+
+  VideoContentMetrics* content_metrics_;
+  VideoFrame resampled_frame_;
+  VPMSpatialResampler* spatial_resampler_;
+  VPMContentAnalysis* ca_;
+  VPMVideoDecimator* vd_;
+  bool enable_ca_;
+  int frame_cnt_;
+
+};
+
+}  // namespace webrtc
+
+#endif // WEBRTC_MODULES_VIDEO_PROCESSING_FRAME_PREPROCESSOR_H_