Reland of Add mechanism to signal DelegatedFrameHost that a surface is about to draw. (patchset #1 id:1 of https://codereview.chromium.org/1407173002/ )

Reason for revert:
Memory failure was fixed in r354541.

Original issue's description:
> Revert of Add mechanism to signal DelegatedFrameHost that a surface is about to draw. (patchset #7 id:120001 of https://codereview.chromium.org/1365793002/ )
>
> Reason for revert:
> Causing memory failures on SurfaceAggregatorValidSurfaceTest.CopyRequest in cc_unittests on
> http://build.chromium.org/p/chromium.memory.fyi/builders/Linux%20MSan%20Tests/builds/10514
> and
> http://build.chromium.org/p/chromium.memory.fyi/builders/Linux%20ChromeOS%20MSan%20Tests/builds/4653
>
> [ RUN      ] SurfaceAggregatorValidSurfaceTest.CopyRequest
> ==31905==WARNING: MemorySanitizer: use-of-uninitialized-value
>     #0 0x7fccb3920f7e in cc::Surface::RequestCopyOfOutput(scoped_ptr\u003Ccc::CopyOutputRequest, base::DefaultDeleter\u003Ccc::CopyOutputRequest> >) cc/surfaces/surface.cc:106:15
>     #1 0x7fccb3942ec9 in cc::SurfaceFactory::RequestCopyOfSurface(cc::SurfaceId, scoped_ptr\u003Ccc::CopyOutputRequest, base::DefaultDeleter\u003Ccc::CopyOutputRequest> >) cc/surfaces/surface_factory.cc:75:3
>     #2 0x7fccb31ce931 in cc::(anonymous namespace)::SurfaceAggregatorValidSurfaceTest_CopyRequest_Test::TestBody() cc/surfaces/surface_aggregator_unittest.cc:285:3
>     #3 0x7fccb33160d2 in HandleExceptionsInMethodIfSupported\u003Ctesting::Test, void> testing/gtest/src/gtest.cc:2458:12
>     #4 0x7fccb33160d2 in testing::Test::Run() testing/gtest/src/gtest.cc:2474:0
>     #5 0x7fccb331972c in testing::TestInfo::Run() testing/gtest/src/gtest.cc:2656:5
>     #6 0x7fccb331b0a2 in testing::TestCase::Run() testing/gtest/src/gtest.cc:2774:5
>     #7 0x7fccb333948b in testing::internal::UnitTestImpl::RunAllTests() testing/gtest/src/gtest.cc:4647:11
>     #8 0x7fccb3338468 in HandleExceptionsInMethodIfSupported\u003Ctesting::internal::UnitTestImpl, bool> testing/gtest/src/gtest.cc:2458:12
>     #9 0x7fccb3338468 in testing::UnitTest::Run() testing/gtest/src/gtest.cc:4255:0
>     #10 0x7fccb32867da in RUN_ALL_TESTS testing/gtest/include/gtest/gtest.h:2237:10
>     #11 0x7fccb32867da in base::TestSuite::Run() base/test/test_suite.cc:230:0
>     #12 0x7fccb327388e in Run base/callback.h:396:12
>     #13 0x7fccb327388e in base::(anonymous namespace)::LaunchUnitTestsInternal(base::Callback\u003Cint ()> const&, int, bool, base::Callback\u003Cvoid ()> const&) base/test/launcher/unit_test_launcher.cc:187:0
>     #14 0x7fccb32730de in base::LaunchUnitTests(int, char**, base::Callback\u003Cint ()> const&) base/test/launcher/unit_test_launcher.cc:426:10
>     #15 0x7fccb0ba0c15 in main cc/test/run_all_unittests.cc:12:10
>     #16 0x7fccaa41076c in __libc_start_main /build/buildd/eglibc-2.15/csu/libc-start.c:226:0
>     #17 0x7fccb0b41ca8 in _start ??:0:0
>
>   Uninitialized value was created by a heap allocation
>     #0 0x7fccb0b9fd92 in operator new(unsigned long) ??:0:0
>     #1 0x7fccb31ce897 in CreateEmptyRequest cc/output/copy_output_request.h:26:28
>     #2 0x7fccb31ce897 in cc::(anonymous namespace)::SurfaceAggregatorValidSurfaceTest_CopyRequest_Test::TestBody() cc/surfaces/surface_aggregator_unittest.cc:283:0
>     #3 0x7fccb33160d2 in HandleExceptionsInMethodIfSupported\u003Ctesting::Test, void> testing/gtest/src/gtest.cc:2458:12
>     #4 0x7fccb33160d2 in testing::Test::Run() testing/gtest/src/gtest.cc:2474:0
>     #5 0x7fccb331972c in testing::TestInfo::Run() testing/gtest/src/gtest.cc:2656:5
>     #6 0x7fccb331b0a2 in testing::TestCase::Run() testing/gtest/src/gtest.cc:2774:5
>     #7 0x7fccb333948b in testing::internal::UnitTestImpl::RunAllTests() testing/gtest/src/gtest.cc:4647:11
>     #8 0x7fccb3338468 in HandleExceptionsInMethodIfSupported\u003Ctesting::internal::UnitTestImpl, bool> testing/gtest/src/gtest.cc:2458:12
>     #9 0x7fccb3338468 in testing::UnitTest::Run() testing/gtest/src/gtest.cc:4255:0
>     #10 0x7fccb32867da in RUN_ALL_TESTS testing/gtest/include/gtest/gtest.h:2237:10
>     #11 0x7fccb32867da in base::TestSuite::Run() base/test/test_suite.cc:230:0
>     #12 0x7fccb327388e in Run base/callback.h:396:12
>     #13 0x7fccb327388e in base::(anonymous namespace)::LaunchUnitTestsInternal(base::Callback\u003Cint ()> const&, int, bool, base::Callback\u003Cvoid ()> const&) base/test/launcher/unit_test_launcher.cc:187:0
>     #14 0x7fccb32730de in base::LaunchUnitTests(int, char**, base::Callback\u003Cint ()> const&) base/test/launcher/unit_test_launcher.cc:426:10
>     #15 0x7fccb0ba0c15 in main cc/test/run_all_unittests.cc:12:10
>     #16 0x7fccaa41076c in __libc_start_main /build/buildd/eglibc-2.15/csu/libc-start.c:226:0
>
> SUMMARY: MemorySanitizer: use-of-uninitialized-value (/tmp/runqXGplV/out/Release/cc_unittests+0x32e1f7e)
> Exiting
>
> Original issue's description:
> > 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
> >
> > Committed: https://crrev.com/5ed9ab93dd9f448aac722483b6adc6b7a14cdf4b
> > Cr-Commit-Position: refs/heads/master@{#354390}
>
> TBR=miu@chromium.org,sadrul@chromium.org,jbauman@chromium.org
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=529378
>
> Committed: https://crrev.com/1b8d59763b4266783794a950eee388ddc110ada6
> Cr-Commit-Position: refs/heads/master@{#354446}

TBR=miu@chromium.org,sadrul@chromium.org,mpearson@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=529378

Review URL: https://codereview.chromium.org/1408173002

Cr-Commit-Position: refs/heads/master@{#354554}

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