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/video_processing_impl.h b/webrtc/modules/video_processing/video_processing_impl.h
new file mode 100644
index 0000000..b71aa82
--- /dev/null
+++ b/webrtc/modules/video_processing/video_processing_impl.h
@@ -0,0 +1,75 @@
+/*
+ *  Copyright (c) 2011 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_MODULES_VIDEO_PROCESSING_VIDEO_PROCESSING_IMPL_H_
+#define WEBRTC_MODULES_VIDEO_PROCESSING_VIDEO_PROCESSING_IMPL_H_
+
+#include "webrtc/base/criticalsection.h"
+#include "webrtc/modules/video_processing/include/video_processing.h"
+#include "webrtc/modules/video_processing/brighten.h"
+#include "webrtc/modules/video_processing/brightness_detection.h"
+#include "webrtc/modules/video_processing/deflickering.h"
+#include "webrtc/modules/video_processing/frame_preprocessor.h"
+
+namespace webrtc {
+class CriticalSectionWrapper;
+
+class VideoProcessingModuleImpl : public VideoProcessingModule {
+ public:
+  VideoProcessingModuleImpl();
+  ~VideoProcessingModuleImpl() override;
+
+  void Reset() override;
+
+  int32_t Deflickering(VideoFrame* frame, FrameStats* stats) override;
+
+  int32_t BrightnessDetection(const VideoFrame& frame,
+                              const FrameStats& stats) override;
+
+  // Frame pre-processor functions
+
+  // Enable temporal decimation
+  void EnableTemporalDecimation(bool enable) override;
+
+  void SetInputFrameResampleMode(VideoFrameResampling resampling_mode) override;
+
+  // Enable content analysis
+  void EnableContentAnalysis(bool enable) override;
+
+  // Set Target Resolution: frame rate and dimension
+  int32_t SetTargetResolution(uint32_t width,
+                              uint32_t height,
+                              uint32_t frame_rate) override;
+
+  void SetTargetFramerate(int frame_rate) override;
+
+  // Get decimated values: frame rate/dimension
+  uint32_t Decimatedframe_rate() override;
+  uint32_t DecimatedWidth() const override;
+  uint32_t DecimatedHeight() const override;
+
+  // Preprocess:
+  // Pre-process incoming frame: Sample when needed and compute content
+  // metrics when enabled.
+  // If no resampling takes place - processed_frame is set to NULL.
+  int32_t PreprocessFrame(const VideoFrame& frame,
+                          VideoFrame** processed_frame) override;
+  VideoContentMetrics* ContentMetrics() const override;
+
+ private:
+  mutable rtc::CriticalSection mutex_;
+  VPMDeflickering deflickering_ GUARDED_BY(mutex_);
+  VPMBrightnessDetection brightness_detection_;
+  VPMFramePreprocessor frame_pre_processor_;
+};
+
+}  // namespace
+
+#endif  // WEBRTC_MODULES_VIDEO_PROCESSING_VIDEO_PROCESSING_IMPL_H_