Add mechanism to signal DelegatedFrameHost that a surface is about to draw.

This allows the FrameSubscriber to request a copy of the output even when the renderer it's subscribing to hasn't changed its contents, but a child renderer (oopif or webview) has.

BUG=529378
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel

Review URL: https://codereview.chromium.org/1365793002

Cr-Commit-Position: refs/heads/master@{#354390}
(cherry picked from commit 5ed9ab93dd9f448aac722483b6adc6b7a14cdf4b)
TBR=miu@chromium.org

Review URL: https://codereview.chromium.org/1413693006 .

Cr-Commit-Position: refs/branch-heads/2526@{#181}
Cr-Branched-From: cb947c0153db0ec02a8abbcb3ca086d88bf6006f-refs/heads/master@{#352221}

10 files changed, 148 insertions, 13 deletions

diff --git a/cc/surfaces/surface.cc b/cc/surfaces/surface.cc
index 16987cb..e3b0f5e 100644
--- a/cc/surfaces/surface.cc
+++ b/cc/surfaces/surface.cc
@@ -98,11 +98,22 @@ void Surface::QueueFrame(scoped_ptr<CompositorFrame> frame,
 
 void Surface::RequestCopyOfOutput(scoped_ptr<CopyOutputRequest> copy_request) {
   if (current_frame_ &&
-      !current_frame_->delegated_frame_data->render_pass_list.empty())
-    current_frame_->delegated_frame_data->render_pass_list.back()
-        ->copy_requests.push_back(copy_request.Pass());
-  else
+      !current_frame_->delegated_frame_data->render_pass_list.empty()) {
+    ScopedPtrVector<CopyOutputRequest>& copy_requests =
+        current_frame_->delegated_frame_data->render_pass_list.back()
+            ->copy_requests;
+
+    if (void* source = copy_request->source()) {
+      // Remove existing CopyOutputRequests made on the Surface by the same
+      // source.
+      auto to_remove = copy_requests.remove_if([source](
+          const CopyOutputRequest* x) { return x->source() == source; });
+      copy_requests.erase(to_remove, copy_requests.end());
+    }
+    copy_requests.push_back(copy_request.Pass());
+  } else {
     copy_request->SendEmptyResult();
+  }
 }
 
 void Surface::TakeCopyOutputRequests(
diff --git a/cc/surfaces/surface_aggregator.cc b/cc/surfaces/surface_aggregator.cc
index 69618ba..902f836 100644
--- a/cc/surfaces/surface_aggregator.cc
+++ b/cc/surfaces/surface_aggregator.cc
@@ -547,9 +547,6 @@ gfx::Rect SurfaceAggregator::PrewalkTree(SurfaceId surface_id) {
   if (provider_)
     provider_->DeclareUsedResourcesFromChild(child_id, referenced_resources);
 
-  for (const auto& render_pass : frame_data->render_pass_list)
-    has_copy_requests_ |= !render_pass->copy_requests.empty();
-
   gfx::Rect damage_rect;
   if (!frame_data->render_pass_list.empty()) {
     RenderPass* last_pass = frame_data->render_pass_list.back();
@@ -566,6 +563,13 @@ gfx::Rect SurfaceAggregator::PrewalkTree(SurfaceId surface_id) {
     damage_rect.Union(
         MathUtil::MapEnclosingClippedRect(surface_info.second, surface_damage));
   }
+
+  if (surface->factory())
+    surface->factory()->WillDrawSurface(surface->surface_id(), damage_rect);
+
+  for (const auto& render_pass : frame_data->render_pass_list)
+    has_copy_requests_ |= !render_pass->copy_requests.empty();
+
   referenced_surfaces_.erase(it);
   return damage_rect;
 }
diff --git a/cc/surfaces/surface_aggregator_unittest.cc b/cc/surfaces/surface_aggregator_unittest.cc
index b2476d9..82f746f 100644
--- a/cc/surfaces/surface_aggregator_unittest.cc
+++ b/cc/surfaces/surface_aggregator_unittest.cc
@@ -43,6 +43,13 @@ gfx::Size SurfaceSize() {
 class EmptySurfaceFactoryClient : public SurfaceFactoryClient {
  public:
   void ReturnResources(const ReturnedResourceArray& resources) override {}
+  void WillDrawSurface(SurfaceId id, const gfx::Rect& damage_rect) override {
+    last_surface_id_ = id;
+    last_damage_rect_ = damage_rect;
+  }
+
+  gfx::Rect last_damage_rect_;
+  SurfaceId last_surface_id_;
 };
 
 class SurfaceAggregatorTest : public testing::Test {
@@ -166,6 +173,10 @@ TEST_F(SurfaceAggregatorValidSurfaceTest, SimpleFrame) {
 
   SurfaceId ids[] = {root_surface_id_};
   AggregateAndVerify(passes, arraysize(passes), ids, arraysize(ids));
+
+  // Check that WillDrawSurface was called.
+  EXPECT_EQ(gfx::Rect(SurfaceSize()), empty_client_.last_damage_rect_);
+  EXPECT_EQ(root_surface_id_, empty_client_.last_surface_id_);
 }
 
 TEST_F(SurfaceAggregatorValidSurfaceTest, OpacityCopied) {
diff --git a/cc/surfaces/surface_factory.cc b/cc/surfaces/surface_factory.cc
index 3e83c8c..72ebdc4 100644
--- a/cc/surfaces/surface_factory.cc
+++ b/cc/surfaces/surface_factory.cc
@@ -8,6 +8,7 @@
 #include "cc/output/compositor_frame.h"
 #include "cc/output/copy_output_request.h"
 #include "cc/surfaces/surface.h"
+#include "cc/surfaces/surface_factory_client.h"
 #include "cc/surfaces/surface_manager.h"
 #include "ui/gfx/geometry/size.h"
 
@@ -75,6 +76,11 @@ void SurfaceFactory::RequestCopyOfSurface(
   manager_->SurfaceModified(surface_id);
 }
 
+void SurfaceFactory::WillDrawSurface(SurfaceId id,
+                                     const gfx::Rect& damage_rect) {
+  client_->WillDrawSurface(id, damage_rect);
+}
+
 void SurfaceFactory::ReceiveFromChild(
     const TransferableResourceArray& resources) {
   holder_.ReceiveFromChild(resources);
diff --git a/cc/surfaces/surface_factory.h b/cc/surfaces/surface_factory.h
index 5af8d2e..762d5a2 100644
--- a/cc/surfaces/surface_factory.h
+++ b/cc/surfaces/surface_factory.h
@@ -11,6 +11,7 @@
 #include "base/containers/scoped_ptr_hash_map.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
+#include "base/observer_list.h"
 #include "cc/output/compositor_frame.h"
 #include "cc/surfaces/surface_id.h"
 #include "cc/surfaces/surface_resource_holder.h"
@@ -55,6 +56,8 @@ class CC_SURFACES_EXPORT SurfaceFactory
   void RequestCopyOfSurface(SurfaceId surface_id,
                             scoped_ptr<CopyOutputRequest> copy_request);
 
+  void WillDrawSurface(SurfaceId id, const gfx::Rect& damage_rect);
+
   SurfaceFactoryClient* client() { return client_; }
 
   void ReceiveFromChild(const TransferableResourceArray& resources);
diff --git a/cc/surfaces/surface_factory_client.h b/cc/surfaces/surface_factory_client.h
index 9866b27..c2a04af 100644
--- a/cc/surfaces/surface_factory_client.h
+++ b/cc/surfaces/surface_factory_client.h
@@ -6,7 +6,9 @@
 #define CC_SURFACES_SURFACE_FACTORY_CLIENT_H_
 
 #include "cc/resources/returned_resource.h"
+#include "cc/surfaces/surface_id.h"
 #include "cc/surfaces/surfaces_export.h"
+#include "ui/gfx/geometry/rect.h"
 
 namespace cc {
 
@@ -15,6 +17,9 @@ class CC_SURFACES_EXPORT SurfaceFactoryClient {
   virtual ~SurfaceFactoryClient() {}
 
   virtual void ReturnResources(const ReturnedResourceArray& resources) = 0;
+
+  virtual void WillDrawSurface(SurfaceId surface_id,
+                               const gfx::Rect& damage_rect) {}
 };
 
 }  // namespace cc
diff --git a/cc/surfaces/surface_factory_unittest.cc b/cc/surfaces/surface_factory_unittest.cc
index c7ce964..9629a4e 100644
--- a/cc/surfaces/surface_factory_unittest.cc
+++ b/cc/surfaces/surface_factory_unittest.cc
@@ -4,6 +4,8 @@
 
 #include "base/bind.h"
 #include "cc/output/compositor_frame.h"
+#include "cc/output/copy_output_request.h"
+#include "cc/output/copy_output_result.h"
 #include "cc/output/delegated_frame_data.h"
 #include "cc/resources/resource_provider.h"
 #include "cc/surfaces/surface.h"
@@ -519,5 +521,61 @@ TEST_F(SurfaceFactoryTest, DestroyCycle) {
   surface_id_ = SurfaceId();
 }
 
+void CopyRequestTestCallback(bool* called,
+                             scoped_ptr<CopyOutputResult> result) {
+  *called = true;
+}
+
+TEST_F(SurfaceFactoryTest, DuplicateCopyRequest) {
+  {
+    scoped_ptr<RenderPass> render_pass(RenderPass::Create());
+    render_pass->referenced_surfaces.push_back(surface_id_);
+    scoped_ptr<DelegatedFrameData> frame_data(new DelegatedFrameData);
+    frame_data->render_pass_list.push_back(render_pass.Pass());
+    scoped_ptr<CompositorFrame> frame(new CompositorFrame);
+    frame->delegated_frame_data = frame_data.Pass();
+    factory_.SubmitCompositorFrame(surface_id_, frame.Pass(),
+                                   SurfaceFactory::DrawCallback());
+  }
+  void* source1 = &source1;
+  void* source2 = &source2;
+
+  bool called1 = false;
+  scoped_ptr<CopyOutputRequest> request;
+  request = CopyOutputRequest::CreateRequest(
+      base::Bind(&CopyRequestTestCallback, &called1));
+  request->set_source(source1);
+
+  factory_.RequestCopyOfSurface(surface_id_, request.Pass());
+  EXPECT_FALSE(called1);
+
+  bool called2 = false;
+  request = CopyOutputRequest::CreateRequest(
+      base::Bind(&CopyRequestTestCallback, &called2));
+  request->set_source(source2);
+
+  factory_.RequestCopyOfSurface(surface_id_, request.Pass());
+  // Callbacks have different sources so neither should be called.
+  EXPECT_FALSE(called1);
+  EXPECT_FALSE(called2);
+
+  bool called3 = false;
+  request = CopyOutputRequest::CreateRequest(
+      base::Bind(&CopyRequestTestCallback, &called3));
+  request->set_source(source1);
+
+  factory_.RequestCopyOfSurface(surface_id_, request.Pass());
+  // Two callbacks are from source1, so the first should be called.
+  EXPECT_TRUE(called1);
+  EXPECT_FALSE(called2);
+  EXPECT_FALSE(called3);
+
+  factory_.Destroy(surface_id_);
+  surface_id_ = SurfaceId();
+  EXPECT_TRUE(called1);
+  EXPECT_TRUE(called2);
+  EXPECT_TRUE(called3);
+}
+
 }  // namespace
 }  // namespace cc
diff --git a/content/browser/compositor/delegated_frame_host.cc b/content/browser/compositor/delegated_frame_host.cc
index abc001e..ca8a0d87 100644
--- a/content/browser/compositor/delegated_frame_host.cc
+++ b/content/browser/compositor/delegated_frame_host.cc
@@ -254,7 +254,7 @@ void DelegatedFrameHost::CheckResizeLock() {
   resize_lock_->UnlockCompositor();
 }
 
-void DelegatedFrameHost::DidReceiveFrameFromRenderer(
+void DelegatedFrameHost::AttemptFrameSubscriberCapture(
     const gfx::Rect& damage_rect) {
   if (!frame_subscriber() || !CanCopyToVideoFrame())
     return;
@@ -298,14 +298,25 @@ void DelegatedFrameHost::DidReceiveFrameFromRenderer(
   // screenshots) since those copy requests do not specify |frame_subscriber()|
   // as a source.
   request->set_source(frame_subscriber());
-  request->set_area(gfx::Rect(current_frame_size_in_dip_));
   if (subscriber_texture.get()) {
     request->SetTextureMailbox(
         cc::TextureMailbox(subscriber_texture->mailbox(),
                            subscriber_texture->target(),
                            subscriber_texture->sync_point()));
   }
-  RequestCopyOfOutput(request.Pass());
+
+  if (surface_factory_.get()) {
+    // To avoid unnecessary composites, go directly to the Surface rather than
+    // through RequestCopyOfOutput (which goes through the browser
+    // compositor).
+    if (!request_copy_of_output_callback_for_testing_.is_null())
+      request_copy_of_output_callback_for_testing_.Run(request.Pass());
+    else
+      surface_factory_->RequestCopyOfSurface(surface_id_, request.Pass());
+  } else {
+    request->set_area(gfx::Rect(current_frame_size_in_dip_));
+    RequestCopyOfOutput(request.Pass());
+  }
 }
 
 void DelegatedFrameHost::SwapDelegatedFrame(
@@ -475,7 +486,10 @@ void DelegatedFrameHost::SwapDelegatedFrame(
   } else {
     AddOnCommitCallbackAndDisableLocks(base::Closure());
   }
-  DidReceiveFrameFromRenderer(damage_rect);
+  // With Surfaces, the notification that the surface will be drawn notifies
+  // the frame subscriber.
+  if (!use_surfaces_)
+    AttemptFrameSubscriberCapture(damage_rect);
   if (frame_provider_.get() || !surface_id_.is_null())
     delegated_frame_evictor_->SwappedFrame(
         client_->DelegatedFrameHostIsVisible());
@@ -536,6 +550,13 @@ void DelegatedFrameHost::ReturnResources(
     SendReturnedDelegatedResources(last_output_surface_id_);
 }
 
+void DelegatedFrameHost::WillDrawSurface(cc::SurfaceId id,
+                                         const gfx::Rect& damage_rect) {
+  if (id != surface_id_)
+    return;
+  AttemptFrameSubscriberCapture(damage_rect);
+}
+
 void DelegatedFrameHost::EvictDelegatedFrame() {
   client_->DelegatedFrameHostGetLayer()->SetShowSolidColorContent();
   frame_provider_ = NULL;
diff --git a/content/browser/compositor/delegated_frame_host.h b/content/browser/compositor/delegated_frame_host.h
index aa3ce5b..c9662cb 100644
--- a/content/browser/compositor/delegated_frame_host.h
+++ b/content/browser/compositor/delegated_frame_host.h
@@ -116,6 +116,7 @@ class CONTENT_EXPORT DelegatedFrameHost
 
   // cc::SurfaceFactoryClient implementation.
   void ReturnResources(const cc::ReturnedResourceArray& resources) override;
+  void WillDrawSurface(cc::SurfaceId id, const gfx::Rect& damage_rect) override;
 
   bool CanCopyToBitmap() const;
 
@@ -246,7 +247,7 @@ class CONTENT_EXPORT DelegatedFrameHost
 
   // Called to consult the current |frame_subscriber_|, to determine and maybe
   // initiate a copy-into-video-frame request.
-  void DidReceiveFrameFromRenderer(const gfx::Rect& damage_rect);
+  void AttemptFrameSubscriberCapture(const gfx::Rect& damage_rect);
 
   DelegatedFrameHostClient* const client_;
   ui::Compositor* compositor_;
diff --git a/content/browser/renderer_host/render_widget_host_view_aura_unittest.cc b/content/browser/renderer_host/render_widget_host_view_aura_unittest.cc
index d360dc9..68a362a 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura_unittest.cc
+++ b/content/browser/renderer_host/render_widget_host_view_aura_unittest.cc
@@ -21,6 +21,7 @@
 #include "content/browser/compositor/resize_lock.h"
 #include "content/browser/compositor/test/no_transport_image_transport_factory.h"
 #include "content/browser/frame_host/render_widget_host_view_guest.h"
+#include "content/browser/gpu/compositor_util.h"
 #include "content/browser/renderer_host/input/input_router.h"
 #include "content/browser/renderer_host/input/web_input_event_util.h"
 #include "content/browser/renderer_host/overscroll_controller.h"
@@ -192,12 +193,14 @@ class TestWindowObserver : public aura::WindowObserver {
 class FakeFrameSubscriber : public RenderWidgetHostViewFrameSubscriber {
  public:
   FakeFrameSubscriber(gfx::Size size, base::Callback<void(bool)> callback)
-      : size_(size), callback_(callback) {}
+      : size_(size), callback_(callback), should_capture_(true) {}
 
   bool ShouldCaptureFrame(const gfx::Rect& damage_rect,
                           base::TimeTicks present_time,
                           scoped_refptr<media::VideoFrame>* storage,
                           DeliverFrameCallback* callback) override {
+    if (!should_capture_)
+      return false;
     last_present_time_ = present_time;
     *storage = media::VideoFrame::CreateFrame(media::PIXEL_FORMAT_YV12, size_,
                                               gfx::Rect(size_), size_,
@@ -208,6 +211,10 @@ class FakeFrameSubscriber : public RenderWidgetHostViewFrameSubscriber {
 
   base::TimeTicks last_present_time() const { return last_present_time_; }
 
+  void set_should_capture(bool should_capture) {
+    should_capture_ = should_capture;
+  }
+
   static void CallbackMethod(base::Callback<void(bool)> callback,
                              base::TimeTicks present_time,
                              bool success) {
@@ -218,6 +225,7 @@ class FakeFrameSubscriber : public RenderWidgetHostViewFrameSubscriber {
   gfx::Size size_;
   base::Callback<void(bool)> callback_;
   base::TimeTicks last_present_time_;
+  bool should_capture_;
 };
 
 class FakeWindowEventDispatcher : public aura::WindowEventDispatcher {
@@ -2236,7 +2244,10 @@ class RenderWidgetHostViewAuraCopyRequestTest
   void RunLoopUntilCallback() {
     base::RunLoop run_loop;
     quit_closure_ = run_loop.QuitClosure();
+    // Temporarily ignore real draw requests.
+    frame_subscriber_->set_should_capture(false);
     run_loop.Run();
+    frame_subscriber_->set_should_capture(true);
   }
 
   void InitializeView() {
@@ -2268,6 +2279,10 @@ class RenderWidgetHostViewAuraCopyRequestTest
   void OnSwapCompositorFrame() {
     view_->OnSwapCompositorFrame(
         1, MakeDelegatedFrame(1.f, view_rect_.size(), view_rect_));
+    cc::SurfaceId surface_id =
+        view_->GetDelegatedFrameHost()->SurfaceIdForTesting();
+    if (!surface_id.is_null())
+      view_->GetDelegatedFrameHost()->WillDrawSurface(surface_id, view_rect_);
     ASSERT_TRUE(view_->last_copy_request_);
   }