Add scroll perf test for protocol in chromoting

remoting/test/scroll_frame_generator.cc

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "remoting/test/scroll_frame_generator.h"
+
+#include "remoting/test/frame_generator_util.h"
+#include "third_party/webrtc/modules/desktop_capture/desktop_geometry.h"
+
+namespace remoting {
+namespace test {
+
+namespace {
+int kScrollSpeedPixelsPerSecond = 500;
+}  // namespace
+
+ScrollFrameGenerator::ScrollFrameGenerator()
+    : base_frame_(LoadDesktopFrameFromPng("test_frame2.png")),
+      start_time_(base::TimeTicks::Now()) {}
+ScrollFrameGenerator::~ScrollFrameGenerator() {}
+
+std::unique_ptr<webrtc::DesktopFrame> ScrollFrameGenerator::GenerateFrame(
+    webrtc::SharedMemoryFactory* shared_memory_factory) {
+  base::TimeTicks now = base::TimeTicks::Now();
+  int position = static_cast<int>(kScrollSpeedPixelsPerSecond *
+                                  (now - start_time_).InSecondsF()) %
+                 base_frame_->size().height();
+  std::unique_ptr<webrtc::DesktopFrame> result(
+      new webrtc::BasicDesktopFrame(base_frame_->size()));
+
+  int top_height = base_frame_->size().height() - position;
+
+  result->CopyPixelsFrom(*base_frame_, webrtc::DesktopVector(0, position),
+                         webrtc::DesktopRect::MakeLTRB(
+                             0, 0, base_frame_->size().width(), top_height));
+  result->CopyPixelsFrom(
+      *base_frame_, webrtc::DesktopVector(0, 0),
+      webrtc::DesktopRect::MakeLTRB(0, top_height, base_frame_->size().width(),
+                                  base_frame_->size().height()));
+
+  result->mutable_updated_region()->SetRect(
+      webrtc::DesktopRect::MakeSize(result->size()));
+
+  ++last_frame_id_;
+  frame_timestamp_[last_frame_id_] = now;
+  DrawBarcode(last_frame_id_, true, result.get());
+
+  return result;
+}
+
+base::TimeDelta ScrollFrameGenerator::GetFrameLatency(
+    const webrtc::DesktopFrame& frame) {
+  int frame_id = ReadBarcode(frame);
+  if (!frame_timestamp_.count(frame_id))
+    LOG(FATAL) << "Unknown frame_id.";
+  return base::TimeTicks::Now() - frame_timestamp_[frame_id];
+}
+
+}  // namespace test
+}  // namespace remoting