Makes ResourceLoader own handles and return Files

components/resource_provider/public/cpp/resource_loader.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/resource_provider/public/cpp/resource_loader.h"
 
 #include "base/bind.h"
+#include "base/files/file.h"
 #include "mojo/common/common_type_converters.h"
 #include "mojo/platform_handle/platform_handle_functions.h"
 #include "third_party/mojo/src/mojo/public/cpp/application/connect.h"
 #include "third_party/mojo/src/mojo/public/interfaces/application/shell.mojom.h"
 
 namespace resource_provider {
 
 ResourceLoader::ResourceLoader(mojo::Shell* shell,
                                const std::set<std::string>& paths)
-    : loaded_(false) {
+    : loaded_(false), did_block_(false) {
   shell->ConnectToApplication("mojo:resource_provider",
                               GetProxy(&resource_provider_service_provider_),
                               nullptr);
   mojo::ConnectToService(resource_provider_service_provider_.get(),
                          &resource_provider_);
   std::vector<std::string> paths_vector(paths.begin(), paths.end());
   resource_provider_->GetResources(
       mojo::Array<mojo::String>::From(paths_vector),
       base::Bind(&ResourceLoader::OnGotResources, base::Unretained(this),
                  paths_vector));
 }
 
 ResourceLoader::~ResourceLoader() {
 }
 
 bool ResourceLoader::BlockUntilLoaded() {
-  CHECK(!loaded_);
+  if (did_block_)
+    return loaded_;
+
+  did_block_ = true;
   resource_provider_.WaitForIncomingMethodCall();
   return loaded_;
 }
 
+base::File ResourceLoader::ReleaseFile(const std::string& path) {
+  CHECK(resource_map_.count(path));
+  scoped_ptr<base::File> file_wrapper(resource_map_[path].Pass());
+  resource_map_.erase(path);
+  return file_wrapper->Pass();
+}
+
 void ResourceLoader::OnGotResources(const std::vector<std::string>& paths,
                                     mojo::Array<mojo::ScopedHandle> resources) {
   // We no longer need the connection to ResourceProvider.
   resource_provider_.reset();
   resource_provider_service_provider_.reset();
 
   CHECK(!resources.is_null());
   CHECK_EQ(resources.size(), paths.size());
   for (size_t i = 0; i < resources.size(); ++i) {
     CHECK(resources[i].is_valid());
     MojoPlatformHandle platform_handle;
     CHECK(MojoExtractPlatformHandle(resources[i].release().value(),
                                     &platform_handle) == MOJO_RESULT_OK);
-    resource_map_[paths[i]] = platform_handle;
+    resource_map_[paths[i]].reset(new base::File(platform_handle));
   }
   loaded_ = true;
 }
 
 }  // namespace resource_provider