cc: Add BeginFrameArgs

cc/output/begin_frame_args.cc

+// Copyright (c) 2013 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 "cc/output/begin_frame_args.h"
+
+namespace cc {
+
+BeginFrameArgs::BeginFrameArgs()
+  : frame_time(base::TimeTicks()),
+    deadline(base::TimeTicks()),
+    interval(base::TimeDelta::FromMicroseconds(-1))
+{
+}
+
+BeginFrameArgs::BeginFrameArgs(base::TimeTicks frame_time,
+                               base::TimeTicks deadline,
+                               base::TimeDelta interval)
+  : frame_time(frame_time),
+    deadline(deadline),
+    interval(interval)
+{}
+
+BeginFrameArgs BeginFrameArgs::Create(base::TimeTicks frame_time,
+                                      base::TimeTicks deadline,
+                                      base::TimeDelta interval) {
+  return BeginFrameArgs(frame_time, deadline, interval);
+}
+
+BeginFrameArgs BeginFrameArgs::CreateForSynchronousCompositor() {
+  // For WebView/SynchronousCompositor, we always want to draw immediately,
+  // so we set the deadline to 0 and guess that the interval is 16 milliseconds.
+  return BeginFrameArgs(base::TimeTicks::Now(),
+                        base::TimeTicks(),
+                        DefaultInterval());
+}
+
+BeginFrameArgs BeginFrameArgs::CreateForTesting() {
+  base::TimeTicks now = base::TimeTicks::Now();
+  return BeginFrameArgs(now,
+                        now + (DefaultInterval() / 2),
+                        DefaultInterval());
+}
+
+base::TimeDelta BeginFrameArgs::DefaultDeadlineAdjustment() {
+  // Using a large deadline adjustment will effectively revert BeginFrame
+  // scheduling to the hard vsync scheduling we used to have.
+  return base::TimeDelta::FromSeconds(-1);
+}
+
+base::TimeDelta BeginFrameArgs::DefaultInterval() {
+  return base::TimeDelta::FromMicroseconds(16666);
+}
+
+}  // namespace cc