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.cc b/webrtc/modules/video_processing/video_processing_impl.cc
new file mode 100644
index 0000000..898b02e
--- /dev/null
+++ b/webrtc/modules/video_processing/video_processing_impl.cc
@@ -0,0 +1,181 @@
+/*
+ *  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.
+ */
+#include "webrtc/base/logging.h"
+#include "webrtc/modules/video_processing/video_processing_impl.h"
+#include "webrtc/system_wrappers/include/critical_section_wrapper.h"
+
+#include <assert.h>
+
+namespace webrtc {
+
+namespace {
+void  SetSubSampling(VideoProcessingModule::FrameStats* stats,
+                     const int32_t width,
+                     const int32_t height) {
+  if (width * height >= 640 * 480) {
+    stats->subSamplWidth = 3;
+    stats->subSamplHeight = 3;
+  } else if (width * height >= 352 * 288) {
+    stats->subSamplWidth = 2;
+    stats->subSamplHeight = 2;
+  } else if (width * height >= 176 * 144) {
+    stats->subSamplWidth = 1;
+    stats->subSamplHeight = 1;
+  } else {
+    stats->subSamplWidth = 0;
+    stats->subSamplHeight = 0;
+  }
+}
+}  // namespace
+
+VideoProcessingModule* VideoProcessingModule::Create() {
+  return new VideoProcessingModuleImpl();
+}
+
+void VideoProcessingModule::Destroy(VideoProcessingModule* module) {
+  if (module)
+    delete static_cast<VideoProcessingModuleImpl*>(module);
+}
+
+VideoProcessingModuleImpl::VideoProcessingModuleImpl() {}
+VideoProcessingModuleImpl::~VideoProcessingModuleImpl() {}
+
+void VideoProcessingModuleImpl::Reset() {
+  rtc::CritScope mutex(&mutex_);
+  deflickering_.Reset();
+  brightness_detection_.Reset();
+  frame_pre_processor_.Reset();
+}
+
+int32_t VideoProcessingModule::GetFrameStats(FrameStats* stats,
+                                             const VideoFrame& frame) {
+  if (frame.IsZeroSize()) {
+    LOG(LS_ERROR) << "Zero size frame.";
+    return VPM_PARAMETER_ERROR;
+  }
+
+  int width = frame.width();
+  int height = frame.height();
+
+  ClearFrameStats(stats);  // The histogram needs to be zeroed out.
+  SetSubSampling(stats, width, height);
+
+  const uint8_t* buffer = frame.buffer(kYPlane);
+  // Compute histogram and sum of frame
+  for (int i = 0; i < height; i += (1 << stats->subSamplHeight)) {
+    int k = i * width;
+    for (int j = 0; j < width; j += (1 << stats->subSamplWidth)) {
+      stats->hist[buffer[k + j]]++;
+      stats->sum += buffer[k + j];
+    }
+  }
+
+  stats->num_pixels = (width * height) / ((1 << stats->subSamplWidth) *
+                     (1 << stats->subSamplHeight));
+  assert(stats->num_pixels > 0);
+
+  // Compute mean value of frame
+  stats->mean = stats->sum / stats->num_pixels;
+
+  return VPM_OK;
+}
+
+bool VideoProcessingModule::ValidFrameStats(const FrameStats& stats) {
+  if (stats.num_pixels == 0) {
+    LOG(LS_WARNING) << "Invalid frame stats.";
+    return false;
+  }
+  return true;
+}
+
+void VideoProcessingModule::ClearFrameStats(FrameStats* stats) {
+  stats->mean = 0;
+  stats->sum = 0;
+  stats->num_pixels = 0;
+  stats->subSamplWidth = 0;
+  stats->subSamplHeight = 0;
+  memset(stats->hist, 0, sizeof(stats->hist));
+}
+
+int32_t VideoProcessingModule::Brighten(VideoFrame* frame, int delta) {
+  return VideoProcessing::Brighten(frame, delta);
+}
+
+int32_t VideoProcessingModuleImpl::Deflickering(VideoFrame* frame,
+                                                FrameStats* stats) {
+  rtc::CritScope mutex(&mutex_);
+  return deflickering_.ProcessFrame(frame, stats);
+}
+
+int32_t VideoProcessingModuleImpl::BrightnessDetection(
+    const VideoFrame& frame,
+    const FrameStats& stats) {
+  rtc::CritScope mutex(&mutex_);
+  return brightness_detection_.ProcessFrame(frame, stats);
+}
+
+
+void VideoProcessingModuleImpl::EnableTemporalDecimation(bool enable) {
+  rtc::CritScope mutex(&mutex_);
+  frame_pre_processor_.EnableTemporalDecimation(enable);
+}
+
+
+void VideoProcessingModuleImpl::SetInputFrameResampleMode(VideoFrameResampling
+                                                          resampling_mode) {
+  rtc::CritScope cs(&mutex_);
+  frame_pre_processor_.SetInputFrameResampleMode(resampling_mode);
+}
+
+int32_t VideoProcessingModuleImpl::SetTargetResolution(uint32_t width,
+                                                       uint32_t height,
+                                                       uint32_t frame_rate) {
+  rtc::CritScope cs(&mutex_);
+  return frame_pre_processor_.SetTargetResolution(width, height, frame_rate);
+}
+
+void VideoProcessingModuleImpl::SetTargetFramerate(int frame_rate) {
+  rtc::CritScope cs(&mutex_);
+  frame_pre_processor_.SetTargetFramerate(frame_rate);
+}
+
+uint32_t VideoProcessingModuleImpl::Decimatedframe_rate() {
+  rtc::CritScope cs(&mutex_);
+  return  frame_pre_processor_.Decimatedframe_rate();
+}
+
+uint32_t VideoProcessingModuleImpl::DecimatedWidth() const {
+  rtc::CritScope cs(&mutex_);
+  return frame_pre_processor_.DecimatedWidth();
+}
+
+uint32_t VideoProcessingModuleImpl::DecimatedHeight() const {
+  rtc::CritScope cs(&mutex_);
+  return frame_pre_processor_.DecimatedHeight();
+}
+
+int32_t VideoProcessingModuleImpl::PreprocessFrame(
+    const VideoFrame& frame,
+    VideoFrame** processed_frame) {
+  rtc::CritScope mutex(&mutex_);
+  return frame_pre_processor_.PreprocessFrame(frame, processed_frame);
+}
+
+VideoContentMetrics* VideoProcessingModuleImpl::ContentMetrics() const {
+  rtc::CritScope mutex(&mutex_);
+  return frame_pre_processor_.ContentMetrics();
+}
+
+void VideoProcessingModuleImpl::EnableContentAnalysis(bool enable) {
+  rtc::CritScope mutex(&mutex_);
+  frame_pre_processor_.EnableContentAnalysis(enable);
+}
+
+}  // namespace webrtc