Modify ScreenCaptureFrameQueue into a template

webrtc/modules/desktop_capture/screen_capturer_mac.mm

Index: webrtc/modules/desktop_capture/screen_capturer_mac.mm
diff --git a/webrtc/modules/desktop_capture/screen_capturer_mac.mm b/webrtc/modules/desktop_capture/screen_capturer_mac.mm
index c41dc4d7a3b4ba59e4ebe6880f1e090dae5386b5..422d514a3aa1db993e77422476cc5814f7e817ba 100644
--- a/webrtc/modules/desktop_capture/screen_capturer_mac.mm
+++ b/webrtc/modules/desktop_capture/screen_capturer_mac.mm
@@ -22,6 +22,7 @@
 #include <OpenGL/CGLMacro.h>
 #include <OpenGL/OpenGL.h>
 
+#include "webrtc/base/checks.h"
 #include "webrtc/base/macutils.h"
 #include "webrtc/modules/desktop_capture/desktop_capture_options.h"
 #include "webrtc/modules/desktop_capture/desktop_frame.h"
@@ -30,8 +31,9 @@
 #include "webrtc/modules/desktop_capture/mac/desktop_configuration.h"
 #include "webrtc/modules/desktop_capture/mac/desktop_configuration_monitor.h"
 #include "webrtc/modules/desktop_capture/mac/scoped_pixel_buffer_object.h"
-#include "webrtc/modules/desktop_capture/screen_capture_frame_queue.h"
+#include "webrtc/modules/desktop_capture/screen_capture_queue.h"
 #include "webrtc/modules/desktop_capture/screen_capturer_helper.h"
+#include "webrtc/modules/desktop_capture/shared_desktop_frame.h"
 #include "webrtc/system_wrappers/include/logging.h"
 #include "webrtc/system_wrappers/include/tick_util.h"
 
@@ -226,7 +228,7 @@ class ScreenCapturerMac : public ScreenCapturer {
                                        void *user_parameter);
   void ReleaseBuffers();
 
-  DesktopFrame* CreateFrame();
+  std::unique_ptr<DesktopFrame> CreateFrame();
 
   Callback* callback_;
 
@@ -234,7 +236,7 @@ class ScreenCapturerMac : public ScreenCapturer {
   ScopedPixelBufferObject pixel_buffer_object_;
 
   // Queue of the frames buffers.
-  ScreenCaptureFrameQueue queue_;
+  ScreenCaptureQueue<SharedDesktopFrame> queue_;
 
   // Current display configuration.
   MacDesktopConfiguration desktop_config_;
@@ -383,7 +385,8 @@ void ScreenCapturerMac::Start(Callback* callback) {
 void ScreenCapturerMac::Capture(const DesktopRegion& region_to_capture) {
   TickTime capture_start_time = TickTime::Now();
 
-  queue_.MoveToNextFrame();
+  queue_.MoveToNext();
+  RTC_DCHECK(!queue_.current() || !queue_.current()->IsShared());
 
   desktop_config_monitor_->Lock();
   MacDesktopConfiguration new_config =
@@ -404,10 +407,10 @@ void ScreenCapturerMac::Capture(const DesktopRegion& region_to_capture) {
   // If the current buffer is from an older generation then allocate a new one.
   // Note that we can't reallocate other buffers at this point, since the caller
   // may still be reading from them.
-  if (!queue_.current_frame())
-    queue_.ReplaceCurrentFrame(CreateFrame());
+  if (!queue_.current())
+    queue_.ReplaceCurrent(SharedDesktopFrame::Wrap(CreateFrame()));
 
-  DesktopFrame* current_frame = queue_.current_frame();
+  DesktopFrame* current_frame = queue_.current();
 
   bool flip = false;  // GL capturers need flipping.
   if (rtc::GetOSVersionName() >= rtc::kMacOSLion) {
@@ -431,7 +434,7 @@ void ScreenCapturerMac::Capture(const DesktopRegion& region_to_capture) {
     CgBlitPreLion(*current_frame, region);
   }
 
-  DesktopFrame* new_frame = queue_.current_frame()->Share();
+  DesktopFrame* new_frame = queue_.current()->Share();
   *new_frame->mutable_updated_region() = region;
 
   if (flip)
@@ -497,7 +500,7 @@ void ScreenCapturerMac::GlBlitFast(const DesktopFrame& frame,
                                    const DesktopRegion& region) {
   // Clip to the size of our current screen.
   DesktopRect clip_rect = DesktopRect::MakeSize(frame.size());
-  if (queue_.previous_frame()) {
+  if (queue_.previous()) {
     // We are doing double buffer for the capture data so we just need to copy
     // the invalid region from the previous capture in the current buffer.
     // TODO(hclam): We can reduce the amount of copying here by subtracting
@@ -512,7 +515,7 @@ void ScreenCapturerMac::GlBlitFast(const DesktopFrame& frame,
       DesktopRect copy_rect = i.rect();
       copy_rect.IntersectWith(clip_rect);
       if (!copy_rect.is_empty()) {
-        CopyRect(queue_.previous_frame()->data() + y_offset,
+        CopyRect(queue_.previous()->data() + y_offset,
                  -frame.stride(),
                  frame.data() + y_offset,
                  -frame.stride(),
@@ -581,9 +584,9 @@ void ScreenCapturerMac::CgBlitPreLion(const DesktopFrame& frame,
   // Copy the entire contents of the previous capture buffer, to capture over.
   // TODO(wez): Get rid of this as per crbug.com/145064, or implement
   // crbug.com/92354.
-  if (queue_.previous_frame()) {
+  if (queue_.previous()) {
     memcpy(frame.data(),
-           queue_.previous_frame()->data(),
+           queue_.previous()->data(),
            frame.stride() * frame.size().height());
   }
 
@@ -636,9 +639,9 @@ bool ScreenCapturerMac::CgBlitPostLion(const DesktopFrame& frame,
   // Copy the entire contents of the previous capture buffer, to capture over.
   // TODO(wez): Get rid of this as per crbug.com/145064, or implement
   // crbug.com/92354.
-  if (queue_.previous_frame()) {
+  if (queue_.previous()) {
     memcpy(frame.data(),
-           queue_.previous_frame()->data(),
+           queue_.previous()->data(),
            frame.stride() * frame.size().height());
   }
 
@@ -964,13 +967,13 @@ void ScreenCapturerMac::ScreenUpdateMoveCallback(
   capturer->ScreenUpdateMove(delta, count, rect_array);
 }
 
-DesktopFrame* ScreenCapturerMac::CreateFrame() {
+std::unique_ptr<DesktopFrame> ScreenCapturerMac::CreateFrame() {
   std::unique_ptr<DesktopFrame> frame(
       new BasicDesktopFrame(screen_pixel_bounds_.size()));
 
   frame->set_dpi(DesktopVector(kStandardDPI * dip_to_pixel_scale_,
                                kStandardDPI * dip_to_pixel_scale_));
-  return frame.release();
+  return frame;
 }
 
 }  // namespace