[mojo talk demo] Convert utility process CheckMediaFile IPC to mojo

chrome/utility/extensions/extensions_handler.cc

Index: chrome/utility/extensions/extensions_handler.cc
diff --git a/chrome/utility/extensions/extensions_handler.cc b/chrome/utility/extensions/extensions_handler.cc
index 787a8b9ef20161ec71ea57e28608859ad392c90b..7b4afeff68c31ef277744e40ac2ca52acfc14865 100644
--- a/chrome/utility/extensions/extensions_handler.cc
+++ b/chrome/utility/extensions/extensions_handler.cc
@@ -12,6 +12,7 @@
 #include "chrome/common/chrome_utility_messages.h"
 #include "chrome/common/extensions/chrome_extensions_client.h"
 #include "chrome/common/extensions/chrome_utility_extensions_messages.h"
+#include "chrome/common/extensions/media_parser.mojom.h"
 #include "chrome/common/media_galleries/metadata_types.h"
 #include "chrome/utility/chrome_content_utility_client.h"
 #include "chrome/utility/media_galleries/ipc_data_source.h"
@@ -22,6 +23,8 @@
 #include "extensions/common/extension_utility_messages.h"
 #include "extensions/utility/unpacker.h"
 #include "media/base/media.h"
+#include "mojo/public/cpp/bindings/strong_binding.h"
+#include "services/service_manager/public/cpp/interface_registry.h"
 #include "ui/base/ui_base_switches.h"
 
 #if !defined(MEDIA_DISABLE_FFMPEG)
@@ -61,6 +64,39 @@ void FinishParseMediaMetadata(
   ReleaseProcessIfNeeded();
 }
 
+class MediaParserImpl : public extensions::mojom::MediaParser {
+ public:
+  MediaParserImpl() = default;
+  ~MediaParserImpl() override = default;
+
+  static void Create(extensions::mojom::MediaParserRequest request) {
+    mojo::MakeStrongBinding(base::MakeUnique<MediaParserImpl>(),
+                            std::move(request));
+  }
+
+ private:
+  // extensions::mojom::MediaParser:
+  void CheckMediaFile(int64_t decode_time_ms,
+                      base::File file,
+                      const CheckMediaFileCallback& callback) override {
+#if !defined(MEDIA_DISABLE_FFMPEG)
+    media::MediaFileChecker checker(std::move(file));
+    const bool check_success =
+        checker.Start(base::TimeDelta::FromMilliseconds(decode_time_ms));
+    callback.Run(check_success);
+#else
+    callback.Run(false);
+#endif
+    // Caller is based on UtilityProcessHostClient and expects the
+    // utility process to manage its own lifetime. TODO(noel): use
+    // utility_process_mojo_client at the call-site to avoid the
+    // need for this release call.
+    ReleaseProcessIfNeeded();
+  }
+
+  DISALLOW_COPY_AND_ASSIGN(MediaParserImpl);
+};
+
 }  // namespace
 
 ExtensionsHandler::ExtensionsHandler(ChromeContentUtilityClient* utility_client)
@@ -77,10 +113,21 @@ void ExtensionsHandler::PreSandboxStartup() {
   media::InitializeMediaLibrary();
 }
 
+// static
+void ExtensionsHandler::ExposeInterfacesToBrowser(
+    service_manager::InterfaceRegistry* registry,
+    bool running_elevated) {
+  // If our process runs with elevated privileges, only add elevated
+  // Mojo services to the service_manager::InterfaceRegistry.
+  if (running_elevated)
+    return;
+
+  registry->AddInterface(base::Bind(&MediaParserImpl::Create));
+}
+
 bool ExtensionsHandler::OnMessageReceived(const IPC::Message& message) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(ExtensionsHandler, message)
-    IPC_MESSAGE_HANDLER(ChromeUtilityMsg_CheckMediaFile, OnCheckMediaFile)
     IPC_MESSAGE_HANDLER(ChromeUtilityMsg_ParseMediaMetadata,
                         OnParseMediaMetadata)
 
@@ -108,21 +155,6 @@ bool ExtensionsHandler::OnMessageReceived(const IPC::Message& message) {
   return handled || utility_handler_.OnMessageReceived(message);
 }
 
-void ExtensionsHandler::OnCheckMediaFile(
-    int64_t milliseconds_of_decoding,
-    const IPC::PlatformFileForTransit& media_file) {
-#if !defined(MEDIA_DISABLE_FFMPEG)
-  media::MediaFileChecker checker(
-      IPC::PlatformFileForTransitToFile(media_file));
-  const bool check_success = checker.Start(
-      base::TimeDelta::FromMilliseconds(milliseconds_of_decoding));
-  Send(new ChromeUtilityHostMsg_CheckMediaFile_Finished(check_success));
-#else
-  Send(new ChromeUtilityHostMsg_CheckMediaFile_Finished(false));
-#endif
-  ReleaseProcessIfNeeded();
-}
-
 void ExtensionsHandler::OnParseMediaMetadata(const std::string& mime_type,
                                              int64_t total_size,
                                              bool get_attached_images) {