cc: Add BeginFrameArgs

cc/output/begin_frame_args.h

+// 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.
+
+#ifndef CC_OUTPUT_BEGIN_FRAME_H_
+#define CC_OUTPUT_BEGIN_FRAME_H_
+
+#include "base/time.h"
+#include "cc/base/cc_export.h"
+
+namespace cc {
+
+struct CC_EXPORT BeginFrameArgs {
+  // Creates an invalid set of values.
+  BeginFrameArgs();
+
+  // You should be able to find all instances where a BeginFrame has been
+  // created by searching for "BeginFrameArgs::Create".
+  static BeginFrameArgs Create(base::TimeTicks frame_time,
+                               base::TimeTicks deadline,
+                               base::TimeDelta interval);
+  static BeginFrameArgs CreateForSynchronousCompositor();
+  static BeginFrameArgs CreateForTesting();
+
+  // This is the default delta that will be used to adjust the deadline when
+  // proper draw-time estimations are not yet available.
+  static base::TimeDelta DefaultDeadlineAdjustment();
+
+  // This is the default interval to use to avoid sprinkling the code with
+  // magic numbers.
+  static base::TimeDelta DefaultInterval();
+
+  bool IsInvalid() const {
+    return interval < base::TimeDelta();
+  }
+
+  base::TimeTicks frame_time;
+  base::TimeTicks deadline;
+  base::TimeDelta interval;
+
+ private:
+  BeginFrameArgs(base::TimeTicks frame_time,
+                 base::TimeTicks deadline,
+                 base::TimeDelta interval);
+};
+
+}  // namespace cc
+
+#endif  // CC_OUTPUT_BEGIN_FRAME_H_