Push frame on RAF for OffscreenCanvas

Only request a dispatcher's begin frame if the current frame hasn't
been uploaded by AnimationFrameProvider

Bug: 995235
Change-Id: I2c6d590d9eed535f4723a65721b3b81dd3f0d449
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1827741
Commit-Queue: Fernando Serboncini <fserb@chromium.org>
Reviewed-by: Khushal <khushalsagar@chromium.org>
Cr-Commit-Position: refs/heads/master@{#701132}

third_party/blink/renderer/core/animation_frame/worker_animation_frame_provider.cc

@@ -41,16 +41,18 @@ void WorkerAnimationFrameProvider::BeginFrame(
   TRACE_EVENT0("blink", "WorkerAnimationFrameProvider::BeginFrame");
 
   double time = (frame_time - base::TimeTicks()).InMillisecondsF();
-
   Microtask::EnqueueMicrotask(WTF::Bind(
       [](base::WeakPtr<WorkerAnimationFrameProvider> provider, double time) {
+        if (!provider)
+          return;
         TRACE_EVENT0("blink",
                      "WorkerAnimationFrameProvider::RequestAnimationFrame");
-        provider->callback_collection_.ExecuteFrameCallbacks(time, time);
-
+        OffscreenCanvas::ScopedInsideWorkerRAF inside_raf_scope;
         for (auto& offscreen_canvas : provider->offscreen_canvases_) {
-          offscreen_canvas->PushFrameIfNeeded();
+          inside_raf_scope.AddOffscreenCanvas(offscreen_canvas);
         }
+
+        provider->callback_collection_.ExecuteFrameCallbacks(time, time);
       },
       weak_factory_.GetWeakPtr(), time));
 }

third_party/blink/renderer/core/offscreencanvas/offscreen_canvas.cc

@@ -404,8 +404,7 @@ void OffscreenCanvas::DidDraw(const FloatRect& rect) {
 
   if (HasPlaceholderCanvas()) {
     needs_push_frame_ = true;
-    // TODO(fserb): perhaps we could avoid requesting begin frames here in cases
-    // where the draw is call from within a worker rAF?
+    if (!inside_worker_raf_)
       GetOrCreateResourceDispatcher()->SetNeedsBeginFrame(true);
   }
 }
@@ -423,13 +422,6 @@ bool OffscreenCanvas::PushFrameIfNeeded() {
   return false;
 }
 
-bool OffscreenCanvas::ShouldAccelerate2dContext() const {
-  base::WeakPtr<WebGraphicsContext3DProviderWrapper> context_provider_wrapper =
-      SharedGpuContext::ContextProviderWrapper();
-  return context_provider_wrapper &&
-         context_provider_wrapper->Utils()->Accelerated2DCanvasFeatureEnabled();
-}
-
 bool OffscreenCanvas::PushFrame(scoped_refptr<CanvasResource> canvas_resource,
                                 const SkIRect& damage_rect) {
   TRACE_EVENT0("blink", "OffscreenCanvas::PushFrame");
@@ -447,6 +439,13 @@ bool OffscreenCanvas::PushFrame(scoped_refptr<CanvasResource> canvas_resource,
   return true;
 }
 
+bool OffscreenCanvas::ShouldAccelerate2dContext() const {
+  base::WeakPtr<WebGraphicsContext3DProviderWrapper> context_provider_wrapper =
+      SharedGpuContext::ContextProviderWrapper();
+  return context_provider_wrapper &&
+         context_provider_wrapper->Utils()->Accelerated2DCanvasFeatureEnabled();
+}
+
 FontSelector* OffscreenCanvas::GetFontSelector() {
   if (auto* document = DynamicTo<Document>(GetExecutionContext())) {
     return document->GetStyleEngine().GetFontSelector();

third_party/blink/renderer/core/offscreencanvas/offscreen_canvas.h

@@ -179,6 +179,30 @@ class CORE_EXPORT OffscreenCanvas final
 
   void Trace(blink::Visitor*) override;
 
+  class ScopedInsideWorkerRAF {
+    STACK_ALLOCATED();
+
+   public:
+    ScopedInsideWorkerRAF() {}
+
+    void AddOffscreenCanvas(OffscreenCanvas* canvas) {
+      DCHECK(!canvas->inside_worker_raf_);
+      canvas->inside_worker_raf_ = true;
+      canvases_.push_back(canvas);
+    }
+
+    ~ScopedInsideWorkerRAF() {
+      for (auto canvas : canvases_) {
+        DCHECK(canvas->inside_worker_raf_);
+        canvas->inside_worker_raf_ = false;
+        canvas->PushFrameIfNeeded();
+      }
+    }
+
+   private:
+    HeapVector<Member<OffscreenCanvas>> canvases_;
+  };
+
  private:
   int32_t memory_usage_ = 0;
 
@@ -195,7 +219,6 @@ class CORE_EXPORT OffscreenCanvas final
 
   IntSize size_;
   bool is_neutered_ = false;
-
   bool origin_clean_ = true;
   bool disable_reading_from_canvas_ = false;
 
@@ -205,6 +228,7 @@ class CORE_EXPORT OffscreenCanvas final
 
   bool needs_matrix_clip_restore_ = false;
   bool needs_push_frame_ = false;
+  bool inside_worker_raf_ = false;
 
   SkFilterQuality filter_quality_ = kLow_SkFilterQuality;