Add support for assets on Fuchsia (#3162)

content_handler/BUILD.gn

@@ -43,7 +43,6 @@ executable("content_handler") {
     "//mojo/public/cpp/bindings",
     "//mojo/public/cpp/system",
     "//mojo/public/interfaces/application",
-    "//mojo/services/asset_bundle/interfaces",
     "//mojo/services/content_handler/interfaces",
     "//mojo/services/framebuffer/interfaces",
     "//mojo/system",

content_handler/runtime_holder.cc

@@ -24,6 +24,7 @@ namespace flutter_content_handler {
 namespace {
 
 constexpr char kSnapshotKey[] = "snapshot_blob.bin";
+constexpr char kAssetPluginChannel[] = "flutter/assets";
 
 // Maximum number of frames in flight.
 constexpr int kMaxPipelineDepth = 3;
@@ -148,6 +149,10 @@ void RuntimeHolder::UpdateSemantics(std::vector<blink::SemanticsNode> update) {}
 
 void RuntimeHolder::HandlePlatformMessage(
     ftl::RefPtr<blink::PlatformMessage> message) {
+  if (message->channel() == kAssetPluginChannel) {
+    HandleAssetPlatformMessage(std::move(message));
+    return;
+  }
   if (auto response = message->response())
     response->CompleteWithError();
 }
@@ -161,7 +166,22 @@ void RuntimeHolder::InitRootBundle(std::vector<char> bundle) {
   root_bundle_data_ = std::move(bundle);
   asset_store_ = ftl::MakeRefCounted<blink::ZipAssetStore>(
       GetUnzipperProviderForRootBundle(), blink::Threads::IO());
-  new blink::ZipAssetBundle(mojo::GetProxy(&root_bundle_), asset_store_);
+}
+
+void RuntimeHolder::HandleAssetPlatformMessage(
+    ftl::RefPtr<blink::PlatformMessage> message) {
+  ftl::RefPtr<blink::PlatformMessageResponse> response = message->response();
+  if (!response)
+    return;
+  const auto& data = message->data();
+  std::string asset_name(reinterpret_cast<const char*>(data.data()),
+                         data.size());
+  std::vector<uint8_t> asset_data;
+  if (asset_store_ && asset_store_->GetAsBuffer(asset_name, &asset_data)) {
+    response->Complete(std::move(asset_data));
+  } else {
+    response->CompleteWithError();
+  }
 }
 
 blink::UnzipperProvider RuntimeHolder::GetUnzipperProviderForRootBundle() {

content_handler/runtime_holder.h

@@ -18,7 +18,6 @@
 #include "lib/ftl/memory/weak_ptr.h"
 #include "mojo/public/cpp/bindings/binding.h"
 #include "mojo/public/interfaces/application/application_connector.mojom.h"
-#include "mojo/services/asset_bundle/interfaces/asset_bundle.mojom.h"
 
 namespace flutter_content_handler {
 class Rasterizer;
@@ -56,6 +55,7 @@ class RuntimeHolder : public blink::RuntimeDelegate,
 
   void InitRootBundle(std::vector<char> bundle);
   blink::UnzipperProvider GetUnzipperProviderForRootBundle();
+  void HandleAssetPlatformMessage(ftl::RefPtr<blink::PlatformMessage> message);
 
   void BeginFrame();
   void OnFrameComplete();
@@ -63,7 +63,6 @@ class RuntimeHolder : public blink::RuntimeDelegate,
 
   std::vector<char> root_bundle_data_;
   ftl::RefPtr<blink::ZipAssetStore> asset_store_;
-  mojo::asset_bundle::AssetBundlePtr root_bundle_;
 
   std::unique_ptr<Rasterizer> rasterizer_;
   std::unique_ptr<blink::RuntimeController> runtime_;