modules/video_coding refactorings

The main purpose was the interface-> include rename, but other files
were also moved, eliminating the "main" dir.

To avoid breaking downstream, the "interface" directories were copied
into a new "video_coding/include" dir. The old headers got pragma
warnings added about deprecation (a very short deprecation since I plan
to remove them as soon downstream is updated).

Other files also moved:
video_coding/main/source -> video_coding
video_coding/main/test -> video_coding/test

BUG=webrtc:5095
TESTED=Passing compile-trybots with --clobber flag:
git cl try --clobber --bot=win_compile_rel --bot=linux_compile_rel --bot=android_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=stefan@webrtc.org, tommi@webrtc.org

Review URL: https://codereview.webrtc.org/1417283007 .

Cr-Commit-Position: refs/heads/master@{#10694}
diff --git a/webrtc/modules/video_coding/timing_unittest.cc b/webrtc/modules/video_coding/timing_unittest.cc
new file mode 100644
index 0000000..02bd88d
--- /dev/null
+++ b/webrtc/modules/video_coding/timing_unittest.cc
@@ -0,0 +1,149 @@
+/*
+ *  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.
+ */
+
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+#include "webrtc/modules/video_coding/include/video_coding.h"
+#include "webrtc/modules/video_coding/internal_defines.h"
+#include "webrtc/modules/video_coding/timing.h"
+#include "webrtc/modules/video_coding/test/test_util.h"
+#include "webrtc/system_wrappers/include/clock.h"
+#include "webrtc/system_wrappers/include/trace.h"
+#include "webrtc/test/testsupport/fileutils.h"
+
+namespace webrtc {
+
+TEST(ReceiverTiming, Tests) {
+  SimulatedClock clock(0);
+  VCMTiming timing(&clock);
+  uint32_t waitTime = 0;
+  uint32_t jitterDelayMs = 0;
+  uint32_t maxDecodeTimeMs = 0;
+  uint32_t timeStamp = 0;
+
+  timing.Reset();
+
+  timing.UpdateCurrentDelay(timeStamp);
+
+  timing.Reset();
+
+  timing.IncomingTimestamp(timeStamp, clock.TimeInMilliseconds());
+  jitterDelayMs = 20;
+  timing.SetJitterDelay(jitterDelayMs);
+  timing.UpdateCurrentDelay(timeStamp);
+  timing.set_render_delay(0);
+  waitTime = timing.MaxWaitingTime(
+      timing.RenderTimeMs(timeStamp, clock.TimeInMilliseconds()),
+      clock.TimeInMilliseconds());
+  // First update initializes the render time. Since we have no decode delay
+  // we get waitTime = renderTime - now - renderDelay = jitter.
+  EXPECT_EQ(jitterDelayMs, waitTime);
+
+  jitterDelayMs += VCMTiming::kDelayMaxChangeMsPerS + 10;
+  timeStamp += 90000;
+  clock.AdvanceTimeMilliseconds(1000);
+  timing.SetJitterDelay(jitterDelayMs);
+  timing.UpdateCurrentDelay(timeStamp);
+  waitTime = timing.MaxWaitingTime(timing.RenderTimeMs(
+      timeStamp, clock.TimeInMilliseconds()), clock.TimeInMilliseconds());
+  // Since we gradually increase the delay we only get 100 ms every second.
+  EXPECT_EQ(jitterDelayMs - 10, waitTime);
+
+  timeStamp += 90000;
+  clock.AdvanceTimeMilliseconds(1000);
+  timing.UpdateCurrentDelay(timeStamp);
+  waitTime = timing.MaxWaitingTime(
+      timing.RenderTimeMs(timeStamp, clock.TimeInMilliseconds()),
+      clock.TimeInMilliseconds());
+  EXPECT_EQ(waitTime, jitterDelayMs);
+
+  // 300 incoming frames without jitter, verify that this gives the exact wait
+  // time.
+  for (int i = 0; i < 300; i++) {
+    clock.AdvanceTimeMilliseconds(1000 / 25);
+    timeStamp += 90000 / 25;
+    timing.IncomingTimestamp(timeStamp, clock.TimeInMilliseconds());
+  }
+  timing.UpdateCurrentDelay(timeStamp);
+  waitTime = timing.MaxWaitingTime(
+      timing.RenderTimeMs(timeStamp, clock.TimeInMilliseconds()),
+      clock.TimeInMilliseconds());
+  EXPECT_EQ(waitTime, jitterDelayMs);
+
+  // Add decode time estimates.
+  for (int i = 0; i < 10; i++) {
+    int64_t startTimeMs = clock.TimeInMilliseconds();
+    clock.AdvanceTimeMilliseconds(10);
+    timing.StopDecodeTimer(timeStamp,
+                           clock.TimeInMilliseconds() - startTimeMs,
+                           clock.TimeInMilliseconds(),
+                           timing.RenderTimeMs(
+                               timeStamp, clock.TimeInMilliseconds()));
+    timeStamp += 90000 / 25;
+    clock.AdvanceTimeMilliseconds(1000 / 25 - 10);
+    timing.IncomingTimestamp(timeStamp, clock.TimeInMilliseconds());
+  }
+  maxDecodeTimeMs = 10;
+  timing.SetJitterDelay(jitterDelayMs);
+  clock.AdvanceTimeMilliseconds(1000);
+  timeStamp += 90000;
+  timing.UpdateCurrentDelay(timeStamp);
+  waitTime = timing.MaxWaitingTime(
+      timing.RenderTimeMs(timeStamp, clock.TimeInMilliseconds()),
+      clock.TimeInMilliseconds());
+  EXPECT_EQ(waitTime, jitterDelayMs);
+
+  uint32_t minTotalDelayMs = 200;
+  timing.set_min_playout_delay(minTotalDelayMs);
+  clock.AdvanceTimeMilliseconds(5000);
+  timeStamp += 5*90000;
+  timing.UpdateCurrentDelay(timeStamp);
+  const int kRenderDelayMs = 10;
+  timing.set_render_delay(kRenderDelayMs);
+  waitTime = timing.MaxWaitingTime(
+      timing.RenderTimeMs(timeStamp, clock.TimeInMilliseconds()),
+      clock.TimeInMilliseconds());
+  // We should at least have minTotalDelayMs - decodeTime (10) - renderTime
+  // (10) to wait.
+  EXPECT_EQ(waitTime, minTotalDelayMs - maxDecodeTimeMs - kRenderDelayMs);
+  // The total video delay should be equal to the min total delay.
+  EXPECT_EQ(minTotalDelayMs, timing.TargetVideoDelay());
+
+  // Reset playout delay.
+  timing.set_min_playout_delay(0);
+  clock.AdvanceTimeMilliseconds(5000);
+  timeStamp += 5*90000;
+  timing.UpdateCurrentDelay(timeStamp);
+}
+
+TEST(ReceiverTiming, WrapAround) {
+  const int kFramerate = 25;
+  SimulatedClock clock(0);
+  VCMTiming timing(&clock);
+  // Provoke a wrap-around. The forth frame will have wrapped at 25 fps.
+  uint32_t timestamp = 0xFFFFFFFFu - 3 * 90000 / kFramerate;
+  for (int i = 0; i < 4; ++i) {
+    timing.IncomingTimestamp(timestamp, clock.TimeInMilliseconds());
+    clock.AdvanceTimeMilliseconds(1000 / kFramerate);
+    timestamp += 90000 / kFramerate;
+    int64_t render_time = timing.RenderTimeMs(0xFFFFFFFFu,
+                                              clock.TimeInMilliseconds());
+    EXPECT_EQ(3 * 1000 / kFramerate, render_time);
+    render_time = timing.RenderTimeMs(89u,  // One second later in 90 kHz.
+                                      clock.TimeInMilliseconds());
+    EXPECT_EQ(3 * 1000 / kFramerate + 1, render_time);
+  }
+}
+
+}  // namespace webrtc