Hide fullscreen rotation jank

content/browser/renderer_host/fullscreen_jank_detector.h

Index: content/browser/renderer_host/fullscreen_jank_detector.h
diff --git a/content/browser/renderer_host/fullscreen_jank_detector.h b/content/browser/renderer_host/fullscreen_jank_detector.h
new file mode 100644
index 0000000000000000000000000000000000000000..b58addf8a8c8c3ec0bbbcdfdb4c081b8be799e5a
--- /dev/null
+++ b/content/browser/renderer_host/fullscreen_jank_detector.h
@@ -0,0 +1,50 @@
+// Copyright (c) 2017 The Chromium Authors. All rights reserved.

[boliu, 2017/07/05 17:39:48]

no (c)

+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CONTENT_BROWSER_RENDERER_HOST_FULLSCREEN_JANK_DETECTOR_H_
+#define CONTENT_BROWSER_RENDERER_HOST_FULLSCREEN_JANK_DETECTOR_H_
+
+#include "base/macros.h"
+#include "content/common/content_export.h"
+#include "ui/gfx/geometry/size.h"
+
+namespace content {
+
+// FullscreenJankDetector receives fullscreen state and sizing changes from
+// RenderWidgetHostViewAndroid and uses that to identify fullscreen transition
+// frames that will look janky.
+class CONTENT_EXPORT FullscreenJankDetector {

[boliu, 2017/07/05 17:39:48]

I get really picky about the word "jank", because it's pretty ambiguous outside
of people working on perf, but for those who do, jank is definitely the wrong
word here.

how about FullscreenTransitionStateMachine?

+ public:
+  FullscreenJankDetector(){};

[boliu, 2017/07/05 17:39:48]

space after (), and no semicolon at the end

+  ~FullscreenJankDetector(){};
+
+  void OnFullscreenStateChanged(bool is_fullscreen);
+  void OnPhysicalBackingSizeChanged(gfx::Size size);
+  void OnFrameMetadataUpdated(bool frame_is_fullscreen, gfx::Size frame_size);
+  bool IsInFullscreenTransition() const;
+
+ private:
+  enum class FullscreenState {
+    kNotFullscreen,
+    kEnteringFullscreen,
+    kFullscreen,
+    kExitingFullscreen,
+    kFullscreenRotation,
+  };
+
+  void UpdateFullscreenState();
+
+  FullscreenState state_ = FullscreenState::kNotFullscreen;
+
+  bool web_contents_is_fullscreen_ = false;
+  bool frame_is_fullscreen_ = false;
+  gfx::Size view_size_;
+  gfx::Size frame_size_;
+
+  DISALLOW_COPY_AND_ASSIGN(FullscreenJankDetector);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_RENDERER_HOST_FULLSCREEN_JANK_DETECTOR_H_