[Media Router] Add DialMediaSinkService and DeviceDescriptionService

chrome/browser/media/router/discovery/dial/safe_dial_device_description_parser.h

Index: chrome/browser/media/router/discovery/dial/safe_dial_device_description_parser.h
diff --git a/chrome/browser/media/router/discovery/dial/safe_dial_device_description_parser.h b/chrome/browser/media/router/discovery/dial/safe_dial_device_description_parser.h
index 87d2db3c2b018bd042aeacf1ff766adb320af04b..130050d0069195789fe05ce01724819a6e2f446c 100644
--- a/chrome/browser/media/router/discovery/dial/safe_dial_device_description_parser.h
+++ b/chrome/browser/media/router/discovery/dial/safe_dial_device_description_parser.h
@@ -10,6 +10,7 @@
 
 #include "base/callback.h"
 #include "base/macros.h"
+#include "base/memory/ref_counted.h"
 #include "base/optional.h"
 #include "base/threading/thread_checker.h"
 #include "chrome/common/media_router/dial_device_description_parser.mojom.h"
@@ -19,7 +20,8 @@ namespace media_router {
 
 // SafeDialDeviceDescriptionParser parses the given device description XML file
 // safely via a utility process. This class runs on IO thread.
-class SafeDialDeviceDescriptionParser {
+class SafeDialDeviceDescriptionParser
+    : public base::RefCounted<SafeDialDeviceDescriptionParser> {
  public:
   // Callback function to be invoked when utility process finishes parsing
   // device description XML.
@@ -34,16 +36,22 @@ class SafeDialDeviceDescriptionParser {
   void Start(const std::string& xml_text,
              const DeviceDescriptionCallback& callback);
 
+  int32_t GetPendingParsingRequests() { return pending_parsing_requests_; }
+
  private:
+  friend class base::RefCounted<SafeDialDeviceDescriptionParser>;
+
   ~SafeDialDeviceDescriptionParser();
 
   // See SafeDialDeviceDescriptionParser::DeviceDescriptionCallback
   void OnParseDeviceDescriptionComplete(
+      const DeviceDescriptionCallback& callback,
       chrome::mojom::DialDeviceDescriptionPtr device_description);
 
   // TODO(crbug.com/702766): Add an enum type describing why utility process
   // fails to parse device description xml.
-  void OnParseDeviceDescriptionFailed();
+  void OnParseDeviceDescriptionFailed(
+      const DeviceDescriptionCallback& callback);
 
   // Utility client used to send device description parsing task to the utility
   // process.
@@ -51,8 +59,8 @@ class SafeDialDeviceDescriptionParser {
       chrome::mojom::DialDeviceDescriptionParser>>
       utility_process_mojo_client_;
 
-  // Only accessed on the IO thread.
-  DeviceDescriptionCallback device_description_callback_;
+  // How many parsing requests are pending.
+  int32_t pending_parsing_requests_;
 
   base::ThreadChecker thread_checker_;