Turn the utility process image decoder into a Mojo service.

chrome/utility/chrome_content_utility_client.cc

 // Copyright (c) 2012 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 "chrome/utility/chrome_content_utility_client.h"
 
 #include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/json/json_reader.h"
 #include "base/memory/ref_counted.h"
 #include "base/time/time.h"
 #include "chrome/common/chrome_utility_messages.h"
 #include "chrome/common/safe_browsing/zip_analyzer.h"
 #include "chrome/common/safe_browsing/zip_analyzer_results.h"
 #include "chrome/utility/chrome_content_utility_ipc_whitelist.h"
 #include "chrome/utility/utility_message_handler.h"
 #include "content/public/child/image_decoder_utils.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/common/service_registry.h"
 #include "content/public/utility/utility_thread.h"
 #include "courgette/courgette.h"
 #include "courgette/third_party/bsdiff.h"
 #include "ipc/ipc_channel.h"
+#include "services/image_decoder/image_decoder_impl.h"
 #include "skia/ext/image_operations.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "third_party/zlib/google/zip.h"
 #include "ui/gfx/codec/jpeg_codec.h"
 #include "ui/gfx/geometry/size.h"
 
 #if !defined(OS_ANDROID)
 #include "chrome/utility/profile_import_handler.h"
 #include "net/proxy/mojo_proxy_resolver_factory_impl.h"
 #endif
@@ skipping 48 matching lines @@
 void CreateProxyResolverFactory(
     mojo::InterfaceRequest<net::interfaces::ProxyResolverFactory> request) {
   // MojoProxyResolverFactoryImpl is strongly bound to the Mojo message pipe it
   // is connected to. When that message pipe is closed, either explicitly on the
   // other end (in the browser process), or by a connection error, this object
   // will be destroyed.
   new net::MojoProxyResolverFactoryImpl(request.Pass());
 }
 #endif  // OS_ANDROID
 
+// A simple Mojo service wrapper that reference counts this utility process.
+template <class Impl, class Request>
+class RefCountingMojoService : public Impl {
+ public:
+  RefCountingMojoService(ChromeContentUtilityClient* utility_client,
+                         Request req)
+      : Impl(req.Pass()), utility_client_(utility_client) {
+    DCHECK(utility_client);
+    utility_client_->MojoRef();
+  }
+  ~RefCountingMojoService() override { utility_client_->MojoUnref(); }
+
+ private:
+  ChromeContentUtilityClient* utility_client_;
+};
+
+template <class Interface, class Impl>
+void CreateMojoService(ChromeContentUtilityClient* utility_client,
+                       mojo::InterfaceRequest<Interface> request) {
+  // The Mojo service implementation is assumed to use a StrongBinding<>, which
+  // causes the implementation to be deleted automatically when the Mojo
+  // connection is closed.
+  new RefCountingMojoService<Impl, mojo::InterfaceRequest<Interface>>(
+      utility_client, request.Pass());
+}
+
 }  // namespace
 
 int64_t ChromeContentUtilityClient::max_ipc_message_size_ =
     IPC::Channel::kMaximumMessageSize;
 
 ChromeContentUtilityClient::ChromeContentUtilityClient()
-    : filter_messages_(false) {
+    : filter_messages_(false), mojo_service_ref_count_(0) {
 #if !defined(OS_ANDROID)
   handlers_.push_back(new ProfileImportHandler());
 #endif
 
 #if defined(ENABLE_EXTENSIONS)
   handlers_.push_back(new extensions::ExtensionsHandler());
   handlers_.push_back(new image_writer::ImageWriterHandler());
 #endif
 
 #if defined(ENABLE_PRINT_PREVIEW) || defined(OS_WIN)
@@ skipping 72 matching lines @@
 
   return handled;
 }
 
 void ChromeContentUtilityClient::RegisterMojoServices(
     content::ServiceRegistry* registry) {
 #if !defined(OS_ANDROID)
   registry->AddService<net::interfaces::ProxyResolverFactory>(
       base::Bind(CreateProxyResolverFactory));
 #endif
+  registry->AddService<services::ImageDecoder>(base::Bind(
+      CreateMojoService<services::ImageDecoder, services::ImageDecoderImpl>,
+      this));
+}
+
+void ChromeContentUtilityClient::MojoRef() {
+  mojo_service_ref_count_++;
+  DCHECK_GT(mojo_service_ref_count_, 0);
+}
+
+void ChromeContentUtilityClient::MojoUnref() {
+  DCHECK_GT(mojo_service_ref_count_, 0);
+  mojo_service_ref_count_--;
+  if (mojo_service_ref_count_ <= 0) {
+    ReleaseProcessIfNeeded();
+  }
 }
 
 // static
 void ChromeContentUtilityClient::PreSandboxStartup() {
 #if defined(ENABLE_EXTENSIONS)
   extensions::ExtensionsHandler::PreSandboxStartup();
 #endif
 
 #if defined(ENABLE_MDNS)
   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
@@ skipping 191 matching lines @@
     const std::string& mime_type, int64 total_size, bool get_attached_images) {
   // Only one IPCDataSource may be created and added to the list of handlers.
   metadata::IPCDataSource* source = new metadata::IPCDataSource(total_size);
   handlers_.push_back(source);
 
   metadata::MediaMetadataParser* parser = new metadata::MediaMetadataParser(
       source, mime_type, get_attached_images);
   parser->Start(base::Bind(&FinishParseMediaMetadata, base::Owned(parser)));
 }
 #endif