"Buttery Smooth" Tab Capture.

content/browser/compositor/delegated_frame_host.cc

 // Copyright 2014 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.
 
 #include "content/browser/compositor/delegated_frame_host.h"
 
 #include "base/callback_helpers.h"
 #include "base/command_line.h"
 #include "cc/output/compositor_frame.h"
 #include "cc/output/compositor_frame_ack.h"
 #include "cc/output/copy_output_request.h"
 #include "cc/resources/single_release_callback.h"
 #include "cc/resources/texture_mailbox.h"
 #include "content/browser/compositor/resize_lock.h"
 #include "content/common/gpu/client/gl_helper.h"
 #include "content/public/browser/render_widget_host_view_frame_subscriber.h"
 #include "content/public/common/content_switches.h"
 #include "media/base/video_frame.h"
 #include "media/base/video_util.h"
 #include "skia/ext/image_operations.h"
+#include "ui/gfx/frame_time.h"
 
 namespace content {
 
 ////////////////////////////////////////////////////////////////////////////////
 // DelegatedFrameHostClient
 
 bool DelegatedFrameHostClient::ShouldCreateResizeLock() {
   // On Windows and Linux, holding pointer moves will not help throttling
   // resizes.
   // TODO(piman): on Windows we need to block (nested message loop?) the
@@ skipping 210 matching lines @@
   // the release of the lock until we've kicked a frame with the new texture, to
   // avoid resizing the UI before we have a chance to draw a "good" frame.
   resize_lock_->UnlockCompositor();
   ui::Compositor* compositor = client_->GetCompositor();
   if (compositor) {
     if (!compositor->HasObserver(this))
       compositor->AddObserver(this);
   }
 }
 
-void DelegatedFrameHost::DidReceiveFrameFromRenderer() {
-  if (frame_subscriber() && CanCopyToVideoFrame()) {
-    const base::TimeTicks present_time = base::TimeTicks::Now();
-    scoped_refptr<media::VideoFrame> frame;
-    RenderWidgetHostViewFrameSubscriber::DeliverFrameCallback callback;
-    if (frame_subscriber()->ShouldCaptureFrame(present_time,
-                                               &frame, &callback)) {
-      CopyFromCompositingSurfaceToVideoFrame(
-          gfx::Rect(current_frame_size_in_dip_),
-          frame,
-          base::Bind(callback, present_time));
-    }
+void DelegatedFrameHost::DidReceiveFrameFromRenderer(
+    const gfx::Rect& damage_rect) {
+  if (!frame_subscriber() || !CanCopyToVideoFrame())
+    return;
+
+  const base::TimeTicks now = gfx::FrameTime::Now();
+  base::TimeTicks present_time;
+  if (vsync_timebase_.is_null() || vsync_interval_ <= base::TimeDelta()) {
+    present_time = now;
+  } else {
+    const int64 intervals_elapsed = (now - vsync_timebase_) / vsync_interval_;
+    present_time = vsync_timebase_ + (intervals_elapsed + 1) * vsync_interval_;
+  }
+
+  scoped_refptr<media::VideoFrame> frame;
+  RenderWidgetHostViewFrameSubscriber::DeliverFrameCallback callback;
+  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(
     uint32 output_surface_id,
     scoped_ptr<cc::DelegatedFrameData> frame_data,
     float frame_device_scale_factor,
     const std::vector<ui::LatencyInfo>& latency_info) {
   RenderWidgetHostImpl* host = client_->GetHost();
   DCHECK(!frame_data->render_pass_list.empty());
@@ skipping 98 matching lines @@
     for (it = skipped_latency_info_list_.begin();
         it != skipped_latency_info_list_.end();
         ++it)
       compositor->SetLatencyInfo(*it);
     skipped_latency_info_list_.clear();
     AddOnCommitCallbackAndDisableLocks(
         base::Bind(&DelegatedFrameHost::SendDelegatedFrameAck,
                    AsWeakPtr(),
                    output_surface_id));
   }
-  DidReceiveFrameFromRenderer();
+  DidReceiveFrameFromRenderer(damage_rect);
   if (frame_provider_.get())
     delegated_frame_evictor_->SwappedFrame(!host->is_hidden());
   // Note: the frame may have been evicted immediately.
 }
 
 void DelegatedFrameHost::SendDelegatedFrameAck(uint32 output_surface_id) {
   RenderWidgetHostImpl* host = client_->GetHost();
   cc::CompositorFrameAck ack;
   if (resource_collection_)
     resource_collection_->TakeUnusedResourcesForChildCompositor(&ack.resources);
@@ skipping 351 matching lines @@
   // A compositor lock that is part of a resize lock timed out. We
   // should display a renderer frame.
   if (!compositor->IsLocked() && can_lock_compositor_ == YES_DID_LOCK) {
     can_lock_compositor_ = NO_PENDING_RENDERER_FRAME;
   }
 }
 
 void DelegatedFrameHost::OnUpdateVSyncParameters(
     base::TimeTicks timebase,
     base::TimeDelta interval) {
+  vsync_timebase_ = timebase;
+  vsync_interval_ = interval;
   RenderWidgetHostImpl* host = client_->GetHost();
   if (client_->IsVisible())
     host->UpdateVSyncParameters(timebase, interval);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // RenderWidgetHostViewAura, ImageTransportFactoryObserver implementation:
 
 void DelegatedFrameHost::OnLostResources() {
   RenderWidgetHostImpl* host = client_->GetHost();
@@ skipping 79 matching lines @@
   // The new_layer is the one that will be used by our Window, so that's the one
   // that should keep our frame. old_layer will be returned to the
   // RecreateLayer caller, and should have a copy.
   if (frame_provider_.get()) {
     new_layer->SetShowDelegatedContent(frame_provider_.get(),
                                        current_frame_size_in_dip_);
   }
 }
 
 }  // namespace content
-