[cc] Fix CompositorFrameSinkSupport BeginFrameAck interface.

third_party/WebKit/Source/platform/graphics/OffscreenCanvasFrameDispatcherImpl.cpp

 // Copyright 2016 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 "platform/graphics/OffscreenCanvasFrameDispatcherImpl.h"
 
 #include "cc/output/compositor_frame.h"
 #include "cc/quads/texture_draw_quad.h"
 #include "gpu/command_buffer/client/gles2_interface.h"
 #include "platform/CrossThreadFunctional.h"
@@ skipping 192 matching lines @@
     called on SwiftShader. */) {
   if (!image || !verifyImageSize(image->size()))
     return;
   if (!m_frameSinkId.is_valid()) {
     postImageToPlaceholder(std::move(image));
     return;
   }
   cc::CompositorFrame frame;
   // TODO(crbug.com/652931): update the device_scale_factor
   frame.metadata.device_scale_factor = 1.0f;
+  if (m_currentBeginFrameAck.sequence_number ==
+      cc::BeginFrameArgs::kInvalidFrameNumber) {
+    // TODO(eseckler): This shouldn't be necessary when OffscreenCanvas no
+    // longer submits CompositorFrames without prior BeginFrame.
+    m_currentBeginFrameAck =
+        cc::BeginFrameAck(cc::BeginFrameArgs::kManualSourceId,
+                          cc::BeginFrameArgs::kStartingFrameNumber,
+                          cc::BeginFrameArgs::kStartingFrameNumber, 0, true);
+  } else {
+    m_currentBeginFrameAck.has_damage = true;
+  }
+  frame.metadata.begin_frame_ack = m_currentBeginFrameAck;
 
   const gfx::Rect bounds(m_width, m_height);
   const int renderPassId = 1;
   std::unique_ptr<cc::RenderPass> pass = cc::RenderPass::Create();
   pass->SetNew(renderPassId, bounds, bounds, gfx::Transform());
   pass->has_transparent_background = false;
 
   cc::SharedQuadState* sqs = pass->CreateAndAppendSharedQuadState();
   sqs->SetAll(gfx::Transform(), bounds.size(), bounds, bounds, false, 1.f,
               SkBlendMode::kSrcOver, 0);
@@ skipping 163 matching lines @@
     bool needsBeginFrame) {
   if (m_sink && needsBeginFrame != m_needsBeginFrame) {
     m_needsBeginFrame = needsBeginFrame;
     m_sink->SetNeedsBeginFrame(needsBeginFrame);
   }
 }
 
 void OffscreenCanvasFrameDispatcherImpl::OnBeginFrame(
     const cc::BeginFrameArgs& beginFrameArgs) {
   DCHECK(client());
+  // TODO(eseckler): Set correct |latest_confirmed_sequence_number|.
+  m_currentBeginFrameAck = cc::BeginFrameAck(
+      beginFrameArgs.source_id, beginFrameArgs.sequence_number,
+      beginFrameArgs.sequence_number, 0, false);
   client()->beginFrame();
+  // TODO(eseckler): Tell |m_sink| if we did not draw during the BeginFrame.
+  m_currentBeginFrameAck.sequence_number =
+      cc::BeginFrameArgs::kInvalidFrameNumber;
 }
 
 void OffscreenCanvasFrameDispatcherImpl::ReclaimResources(
     const cc::ReturnedResourceArray& resources) {
   for (const auto& resource : resources) {
     RefPtr<StaticBitmapImage> image = m_cachedImages.at(resource.id);
 
     if (image) {
       if (image->hasMailbox()) {
         image->updateSyncToken(resource.sync_token);
@@ skipping 44 matching lines @@
 
 void OffscreenCanvasFrameDispatcherImpl::reshape(int width, int height) {
   if (m_width != width || m_height != height) {
     m_width = width;
     m_height = height;
     m_changeSizeForNextCommit = true;
   }
 }
 
 }  // namespace blink