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}

7 files changed, 105 insertions, 7 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 bfec6e6..bee479c 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