Revert of "Route DXGI Frame Statistics to VSyncProvider"

ui/gl/sync_control_vsync_provider.h

 // Copyright 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 UI_GL_SYNC_CONTROL_VSYNC_PROVIDER_H_
 #define UI_GL_SYNC_CONTROL_VSYNC_PROVIDER_H_
 
 #include <stdint.h>
 
 #include <queue>
 
 #include "base/macros.h"
 #include "ui/gfx/vsync_provider.h"
-#include "ui/gl/gl_export.h"
 
 namespace gl {
 
 // Base class for providers based on extensions like GLX_OML_sync_control and
 // EGL_CHROMIUM_sync_control.
-class GL_EXPORT SyncControlVSyncProvider : public gfx::VSyncProvider {
+class SyncControlVSyncProvider : public gfx::VSyncProvider {
  public:
   SyncControlVSyncProvider();
   ~SyncControlVSyncProvider() override;
 
   void GetVSyncParameters(const UpdateVSyncCallback& callback) override;
 
  protected:
   virtual bool GetSyncValues(int64_t* system_time,
                              int64_t* media_stream_counter,
                              int64_t* swap_buffer_counter) = 0;
 
   virtual bool GetMscRate(int32_t* numerator, int32_t* denominator) = 0;
 
  private:
-#if defined(OS_LINUX) || defined(OS_WIN)
-  bool AdjustSyncValues(int64_t* system_time, int64_t* media_stream_counter);
-
+#if defined(OS_LINUX)
   base::TimeTicks last_timebase_;
-  base::TimeDelta last_timebase_diff_;
-  int64_t last_media_stream_counter_ = 0;
-  int64_t last_counter_diff_ = 0;
+  uint64_t last_media_stream_counter_ = 0;
   base::TimeDelta last_good_interval_;
+  bool invalid_msc_ = false;
 
   // A short history of the last few computed intervals.
   // We use this to filter out the noise in the computation resulting
   // from configuration change (monitor reconfiguration, moving windows
   // between monitors, suspend and resume, etc.).
   std::queue<base::TimeDelta> last_computed_intervals_;
-#endif  //  defined(OS_LINUX) || defined(OS_WIN)
-
-#if defined(OS_LINUX)
-  bool invalid_msc_ = false;
 #endif  // defined(OS_LINUX)
 
   DISALLOW_COPY_AND_ASSIGN(SyncControlVSyncProvider);
 };
 
 }  // namespace gl
 
 #endif  // UI_GL_SYNC_CONTROL_VSYNC_PROVIDER_H_