fuchsia: Add FuchsiaExternalViewEmbedder tests

ci/licenses_golden/licenses_flutter

@@ -1462,6 +1462,7 @@ FILE: ../../../flutter/shell/platform/fuchsia/flutter/runner_tzdata_unittest.cc
 FILE: ../../../flutter/shell/platform/fuchsia/flutter/runner_unittest.cc
 FILE: ../../../flutter/shell/platform/fuchsia/flutter/surface.cc
 FILE: ../../../flutter/shell/platform/fuchsia/flutter/surface.h
+FILE: ../../../flutter/shell/platform/fuchsia/flutter/surface_producer.h
 FILE: ../../../flutter/shell/platform/fuchsia/flutter/task_runner_adapter.cc
 FILE: ../../../flutter/shell/platform/fuchsia/flutter/task_runner_adapter.h
 FILE: ../../../flutter/shell/platform/fuchsia/flutter/unique_fdio_ns.h

shell/platform/fuchsia/flutter/BUILD.gn

@@ -90,6 +90,7 @@ template("runner_sources") {
       "runner.h",
       "surface.cc",
       "surface.h",
+      "surface_producer.h",
       "task_runner_adapter.cc",
       "task_runner_adapter.h",
       "unique_fdio_ns.h",
@@ -465,6 +466,7 @@ executable("flutter_runner_unittests") {
     "tests/engine_unittests.cc",
     "tests/fake_session_unittests.cc",
     "tests/flutter_runner_product_configuration_unittests.cc",
+    "tests/fuchsia_external_view_embedder_unittests.cc",
     "tests/gfx_session_connection_unittests.cc",
   ]
 

shell/platform/fuchsia/flutter/flatland_external_view_embedder.cc

@@ -17,7 +17,7 @@ FlatlandExternalViewEmbedder::FlatlandExternalViewEmbedder(
     fidl::InterfaceRequest<fuchsia::ui::composition::ParentViewportWatcher>
         parent_viewport_watcher_request,
     FlatlandConnection& flatland,
-    VulkanSurfaceProducer& surface_producer,
+    SurfaceProducer& surface_producer,
     bool intercept_all_input)
     : flatland_(flatland), surface_producer_(surface_producer) {
   flatland_.flatland()->CreateView(std::move(view_creation_token),
@@ -309,7 +309,7 @@ void FlatlandExternalViewEmbedder::SubmitFrame(
   {
     TRACE_EVENT0("flutter", "PresentSurfaces");
 
-    surface_producer_.OnSurfacesPresented(std::move(frame_surfaces));
+    surface_producer_.SubmitSurfaces(std::move(frame_surfaces));
   }
 
   // Submit the underlying render-backend-specific frame for processing.

shell/platform/fuchsia/flutter/flatland_external_view_embedder.h

@@ -25,11 +25,8 @@
 #include "third_party/skia/include/core/SkSize.h"
 #include "third_party/skia/include/gpu/GrDirectContext.h"
 
-#include "flutter/flow/embedded_views.h"
-#include "flutter/fml/macros.h"
-
 #include "flatland_connection.h"
-#include "vulkan_surface_producer.h"
+#include "surface_producer.h"
 
 namespace flutter_runner {
 
@@ -50,7 +47,7 @@ class FlatlandExternalViewEmbedder final
       fidl::InterfaceRequest<fuchsia::ui::composition::ParentViewportWatcher>
           parent_viewport_watcher_request,
       FlatlandConnection& flatland,
-      VulkanSurfaceProducer& surface_producer,
+      SurfaceProducer& surface_producer,
       bool intercept_all_input = false);
   ~FlatlandExternalViewEmbedder();
 
@@ -167,7 +164,7 @@ class FlatlandExternalViewEmbedder final
   };
 
   FlatlandConnection& flatland_;
-  VulkanSurfaceProducer& surface_producer_;
+  SurfaceProducer& surface_producer_;
   fuchsia::ui::composition::ParentViewportWatcherPtr parent_viewport_watcher_;
 
   fuchsia::ui::composition::TransformId root_transform_id_;

shell/platform/fuchsia/flutter/fuchsia_external_view_embedder.cc

@@ -17,12 +17,6 @@
 namespace flutter_runner {
 namespace {
 
-// Layer separation is as infinitesimal as possible without introducing
-// Z-fighting.
-constexpr float kScenicZElevationBetweenLayers = 0.0001f;
-constexpr float kScenicZElevationForPlatformView = 100.f;
-constexpr float kScenicElevationForInputInterceptor = 500.f;
-
 ViewMutators ParseMutatorStack(const flutter::MutatorsStack& mutators_stack) {
   ViewMutators mutators;
   SkMatrix total_transform = SkMatrix::I();
@@ -110,7 +104,7 @@ FuchsiaExternalViewEmbedder::FuchsiaExternalViewEmbedder(
     fuchsia::ui::views::ViewToken view_token,
     scenic::ViewRefPair view_ref_pair,
     GfxSessionConnection& session,
-    VulkanSurfaceProducer& surface_producer,
+    SurfaceProducer& surface_producer,
     bool intercept_all_input)
     : session_(session),
       surface_producer_(surface_producer),
@@ -491,7 +485,7 @@ void FuchsiaExternalViewEmbedder::SubmitFrame(
         // This does not cause visual problems in practice, but probably has
         // performance implications.
         const SkAlpha layer_opacity =
-            first_layer ? SK_AlphaOPAQUE : SK_AlphaOPAQUE - 1;
+            first_layer ? kBackgroundLayerOpacity : kOverlayLayerOpacity;
         const float layer_elevation =
             kScenicZElevationBetweenLayers * scenic_layer_index +
             embedded_views_height;
@@ -569,7 +563,7 @@ void FuchsiaExternalViewEmbedder::SubmitFrame(
   {
     TRACE_EVENT0("flutter", "PresentSurfaces");
 
-    surface_producer_.OnSurfacesPresented(std::move(frame_surfaces));
+    surface_producer_.SubmitSurfaces(std::move(frame_surfaces));
   }
 
   // Submit the underlying render-backend-specific frame for processing.

shell/platform/fuchsia/flutter/fuchsia_external_view_embedder.h

@@ -28,7 +28,7 @@
 #include "third_party/skia/include/gpu/GrDirectContext.h"
 
 #include "gfx_session_connection.h"
-#include "vulkan_surface_producer.h"
+#include "surface_producer.h"
 
 namespace flutter_runner {
 
@@ -64,11 +64,19 @@ struct ViewMutators {
 // correctly in a unified scene.
 class FuchsiaExternalViewEmbedder final : public flutter::ExternalViewEmbedder {
  public:
+  // Layer separation is as infinitesimal as possible without introducing
+  // Z-fighting.
+  constexpr static float kScenicZElevationBetweenLayers = 0.0001f;
+  constexpr static float kScenicZElevationForPlatformView = 100.f;
+  constexpr static float kScenicElevationForInputInterceptor = 500.f;
+  constexpr static SkAlpha kBackgroundLayerOpacity = SK_AlphaOPAQUE;
+  constexpr static SkAlpha kOverlayLayerOpacity = SK_AlphaOPAQUE - 1;
+
   FuchsiaExternalViewEmbedder(std::string debug_label,
                               fuchsia::ui::views::ViewToken view_token,
                               scenic::ViewRefPair view_ref_pair,
                               GfxSessionConnection& session,
-                              VulkanSurfaceProducer& surface_producer,
+                              SurfaceProducer& surface_producer,
                               bool intercept_all_input = false);
   ~FuchsiaExternalViewEmbedder();
 
@@ -170,7 +178,7 @@ class FuchsiaExternalViewEmbedder final : public flutter::ExternalViewEmbedder {
   };
 
   GfxSessionConnection& session_;
-  VulkanSurfaceProducer& surface_producer_;
+  SurfaceProducer& surface_producer_;
 
   scenic::View root_view_;
   scenic::EntityNode metrics_node_;

shell/platform/fuchsia/flutter/gfx_session_connection.cc

@@ -249,11 +249,9 @@ GfxSessionConnection::GfxSessionConnection(
         // Scenic retired a given number of frames, so mark them as completed.
         // Inspect updates must run on the inspect dispatcher.
         async::PostTask(
-            inspect_dispatcher_,
-            [this, num_presents_handled,
-             now = fml::TimePoint::Now().ToEpochDelta().ToNanoseconds()]() {
+            inspect_dispatcher_, [this, now = Now(), num_presents_handled]() {
               presents_completed_.Add(num_presents_handled);
-              last_frame_completed_.Set(now);
+              last_frame_completed_.Set(now.ToEpochDelta().ToNanoseconds());
             });
 
         if (fire_callback_request_pending_) {
@@ -300,17 +298,15 @@ void GfxSessionConnection::Present() {
                    next_present_session_trace_id_);
   ++next_present_session_trace_id_;
 
-  auto now = fml::TimePoint::Now();
+  auto now = Now();
   present_requested_time_ = now;
 
   // Flutter is requesting a frame here, so mark it as such.
   // Inspect updates must run on the inspect dispatcher.
-  async::PostTask(
-      inspect_dispatcher_,
-      [this, now = fml::TimePoint::Now().ToEpochDelta().ToNanoseconds()]() {
-        presents_requested_.Add(1);
-        last_frame_requested_.Set(now);
-      });
+  async::PostTask(inspect_dispatcher_, [this, now]() {
+    presents_requested_.Add(1);
+    last_frame_requested_.Set(now.ToEpochDelta().ToNanoseconds());
+  });
 
   // Throttle frame submission to Scenic if we already have the maximum amount
   // of frames in flight. This allows the paint tasks for this frame to execute
@@ -333,12 +329,10 @@ void GfxSessionConnection::AwaitVsync(FireCallbackCallback callback) {
 
   // Flutter is requesting a vsync here, so mark it as such.
   // Inspect updates must run on the inspect dispatcher.
-  async::PostTask(
-      inspect_dispatcher_,
-      [this, now = fml::TimePoint::Now().ToEpochDelta().ToNanoseconds()]() {
-        vsyncs_requested_.Add(1);
-        last_vsync_requested_.Set(now);
-      });
+  async::PostTask(inspect_dispatcher_, [this, now = Now()]() {
+    vsyncs_requested_.Add(1);
+    last_vsync_requested_.Set(now.ToEpochDelta().ToNanoseconds());
+  });
 
   FireCallbackMaybe();
 }
@@ -352,12 +346,10 @@ void GfxSessionConnection::AwaitVsyncForSecondaryCallback(
 
   // Flutter is requesting a secondary vsync here, so mark it as such.
   // Inspect updates must run on the inspect dispatcher.
-  async::PostTask(
-      inspect_dispatcher_,
-      [this, now = fml::TimePoint::Now().ToEpochDelta().ToNanoseconds()]() {
-        secondary_vsyncs_completed_.Add(1);
-        last_secondary_vsync_completed_.Set(now);
-      });
+  async::PostTask(inspect_dispatcher_, [this, now = Now()]() {
+    secondary_vsyncs_completed_.Add(1);
+    last_secondary_vsync_completed_.Set(now.ToEpochDelta().ToNanoseconds());
+  });
 
   FlutterFrameTimes times = GetTargetTimesHelper(/*secondary_callback=*/true);
   fire_callback_(times.frame_start, times.frame_target);
@@ -391,12 +383,10 @@ void GfxSessionConnection::PresentSession() {
 
   // Flutter is presenting a frame here, so mark it as such.
   // Inspect updates must run on the inspect dispatcher.
-  async::PostTask(
-      inspect_dispatcher_,
-      [this, now = fml::TimePoint::Now().ToEpochDelta().ToNanoseconds()]() {
-        presents_submitted_.Add(1);
-        last_frame_presented_.Set(now);
-      });
+  async::PostTask(inspect_dispatcher_, [this, now = Now()]() {
+    presents_submitted_.Add(1);
+    last_frame_presented_.Set(now.ToEpochDelta().ToNanoseconds());
+  });
 
   session_wrapper_.Present2(
       /*requested_presentation_time=*/next_latch_point.ToEpochDelta()
@@ -441,12 +431,10 @@ void GfxSessionConnection::FireCallbackMaybe() {
 
     // Scenic completed a vsync here, so mark it as such.
     // Inspect updates must run on the inspect dispatcher.
-    async::PostTask(
-        inspect_dispatcher_,
-        [this, now = fml::TimePoint::Now().ToEpochDelta().ToNanoseconds()]() {
-          vsyncs_completed_.Add(1);
-          last_vsync_completed_.Set(now);
-        });
+    async::PostTask(inspect_dispatcher_, [this, now = Now()]() {
+      vsyncs_completed_.Add(1);
+      last_vsync_completed_.Set(now.ToEpochDelta().ToNanoseconds());
+    });
 
     fire_callback_(times.frame_start, times.frame_target);
   } else {

shell/platform/fuchsia/flutter/surface_producer.h

@@ -0,0 +1,78 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef FLUTTER_SHELL_PLATFORM_FUCHSIA_FLUTTER_SURFACE_PRODUCER_H_
+#define FLUTTER_SHELL_PLATFORM_FUCHSIA_FLUTTER_SURFACE_PRODUCER_H_
+
+#include <fuchsia/ui/composition/cpp/fidl.h>
+#include <lib/zx/event.h>
+
+#include <functional>
+#include <memory>
+#include <vector>
+
+#include "third_party/skia/include/core/SkSize.h"
+#include "third_party/skia/include/core/SkSurface.h"
+
+namespace flutter_runner {
+
+using ReleaseImageCallback = std::function<void()>;
+
+// This represents an abstract notion of a "rendering surface", which is a
+// destination for pixels drawn by some rendering engine.  In this case, the
+// rendering engine is Skia combined with one of its rendering backends.
+//
+// In addition to allowing Skia-based drawing via `GetSkiaSurface`, this
+// rendering surface can be shared with Scenic via `SetImageId`,
+// `GetBufferCollectionImportToken`, `GetAcquireFene`, and `GetReleaseFence`.
+class SurfaceProducerSurface {
+ public:
+  virtual ~SurfaceProducerSurface() = default;
+
+  virtual bool IsValid() const = 0;
+
+  virtual SkISize GetSize() const = 0;
+
+  virtual void SetImageId(uint32_t image_id) = 0;
+
+  virtual uint32_t GetImageId() = 0;
+
+  virtual sk_sp<SkSurface> GetSkiaSurface() const = 0;
+
+  virtual fuchsia::ui::composition::BufferCollectionImportToken
+  GetBufferCollectionImportToken() = 0;
+
+  virtual zx::event GetAcquireFence() = 0;
+
+  virtual zx::event GetReleaseFence() = 0;
+
+  virtual void SetReleaseImageCallback(
+      ReleaseImageCallback release_image_callback) = 0;
+
+  virtual size_t AdvanceAndGetAge() = 0;
+
+  virtual bool FlushSessionAcquireAndReleaseEvents() = 0;
+
+  virtual void SignalWritesFinished(
+      const std::function<void(void)>& on_writes_committed) = 0;
+};
+
+// This represents an abstract notion of "surface producer", which serves as a
+// source for `SurfaceProducerSurface`s.  Produces surfaces should be returned
+// to this `SurfaceProducer` via `SubmitSurfaces`, at which point they will be
+// shared with Scenic.
+class SurfaceProducer {
+ public:
+  virtual ~SurfaceProducer() = default;
+
+  virtual std::unique_ptr<SurfaceProducerSurface> ProduceSurface(
+      const SkISize& size) = 0;
+
+  virtual void SubmitSurfaces(
+      std::vector<std::unique_ptr<SurfaceProducerSurface>> surfaces) = 0;
+};
+
+}  // namespace flutter_runner
+
+#endif  // FLUTTER_SHELL_PLATFORM_FUCHSIA_FLUTTER_SURFACE_PRODUCER_H_