Revert of De-dupe copy requests for tab capture in DelegatedFrameHost.

content/browser/compositor/delegated_frame_host.cc

Index: content/browser/compositor/delegated_frame_host.cc
diff --git a/content/browser/compositor/delegated_frame_host.cc b/content/browser/compositor/delegated_frame_host.cc
index 026e0e0dba7c2dedfe362aa361ca5f1130d9162b..e6cb16150673df0c4db6cc80b28610e4154792a2 100644
--- a/content/browser/compositor/delegated_frame_host.cc
+++ b/content/browser/compositor/delegated_frame_host.cc
@@ -64,7 +64,6 @@
       skipped_frames_(false),
       current_scale_factor_(1.f),
       can_lock_compositor_(YES_CAN_LOCK),
-      frame_subscriber_copy_request_pending_(false),
       delegated_frame_evictor_(new DelegatedFrameEvictor(this)) {
   ImageTransportFactory::GetInstance()->AddObserver(this);
 }
@@ -268,38 +267,13 @@
 
   scoped_refptr<media::VideoFrame> frame;
   RenderWidgetHostViewFrameSubscriber::DeliverFrameCallback callback;
-  if (!frame_subscriber()->ShouldCaptureFrame(damage_rect, present_time,
-                                              &frame, &callback))
-    return;
-
-  if (frame_subscriber_copy_request_pending_) {
-    // A copy request was made for the previous frame from the renderer, but
-    // drawing never started (which executes the request).  Therefore, the
-    // prior frame subscriber delivery callback is to be aborted and the current
-    // one will be run when the existing copy request completes.  This de-duping
-    // check must be done after the call to ShouldCaptureFrame() above, since
-    // the frame subscriber makes decisions based on the renderer's intentions,
-    // and not the performance of the browser compositor.
-    DCHECK(!frame_subscriber_callbacks_.empty());
-    frame_subscriber_callbacks_.back().Run(false);
-    frame_subscriber_callbacks_.back() = base::Bind(callback, present_time);
-    return;
-  }
-
-  // Start a new copy request.
-  frame_subscriber_copy_request_pending_ = true;
-  frame_subscriber_callbacks_.push_back(base::Bind(callback, present_time));
-  CopyFromCompositingSurfaceToVideoFrame(
-      gfx::Rect(current_frame_size_in_dip_),
-      frame,
-      base::Bind(&DelegatedFrameHost::DeliverResultForFrameSubscriber,
-                 AsWeakPtr()));
-}
-
-void DelegatedFrameHost::DeliverResultForFrameSubscriber(bool success) {
-  DCHECK(!frame_subscriber_callbacks_.empty());
-  frame_subscriber_callbacks_.front().Run(success);
-  frame_subscriber_callbacks_.pop_front();
+  if (frame_subscriber()->ShouldCaptureFrame(damage_rect, present_time,
+                                             &frame, &callback)) {
+    CopyFromCompositingSurfaceToVideoFrame(
+        gfx::Rect(current_frame_size_in_dip_),
+        frame,
+        base::Bind(callback, present_time));
+  }
 }
 
 void DelegatedFrameHost::SwapDelegatedFrame(
@@ -880,7 +854,6 @@
 void DelegatedFrameHost::OnCompositingStarted(
     ui::Compositor* compositor, base::TimeTicks start_time) {
   last_draw_ended_ = start_time;
-  frame_subscriber_copy_request_pending_ = false;
 }
 
 void DelegatedFrameHost::OnCompositingEnded(
@@ -930,11 +903,6 @@
 // DelegatedFrameHost, private:
 
 DelegatedFrameHost::~DelegatedFrameHost() {
-  while (!frame_subscriber_callbacks_.empty()) {
-    frame_subscriber_callbacks_.front().Run(false);
-    frame_subscriber_callbacks_.pop_front();
-  }
-
   DCHECK(!compositor_);
   ImageTransportFactory::GetInstance()->RemoveObserver(this);