[Chromecast] Cleanup the API for creating MediaPipelineBackend.

chromecast/browser/cast_browser_main_parts.h

Index: chromecast/browser/cast_browser_main_parts.h
diff --git a/chromecast/browser/cast_browser_main_parts.h b/chromecast/browser/cast_browser_main_parts.h
index 4b5b5d8dfb9bdcfcba6cd59d9ba23ab10ffcaab9..6acd6d00f26095d537557ef3325d63eec329442a 100644
--- a/chromecast/browser/cast_browser_main_parts.h
+++ b/chromecast/browser/cast_browser_main_parts.h
@@ -6,15 +6,10 @@
 #define CHROMECAST_BROWSER_CAST_BROWSER_MAIN_PARTS_H_
 
 #include "base/macros.h"
-#include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "content/public/browser/browser_main_parts.h"
 #include "content/public/common/main_function_params.h"
 
-namespace media {
-class AudioManagerFactory;
-}
-
 namespace net {
 class NetLog;
 }
@@ -27,10 +22,8 @@ class URLRequestContextFactory;
 class CastBrowserMainParts : public content::BrowserMainParts {
  public:
   // This class does not take ownership of |url_request_content_factory|.
-  CastBrowserMainParts(
-      const content::MainFunctionParams& parameters,
-      URLRequestContextFactory* url_request_context_factory,
-      scoped_ptr<::media::AudioManagerFactory> audio_manager_factory);
+  CastBrowserMainParts(const content::MainFunctionParams& parameters,
+                       URLRequestContextFactory* url_request_context_factory);
   ~CastBrowserMainParts() override;
 
   // content::BrowserMainParts implementation:
@@ -45,7 +38,6 @@ class CastBrowserMainParts : public content::BrowserMainParts {
   scoped_ptr<CastBrowserProcess> cast_browser_process_;
   const content::MainFunctionParams parameters_;  // For running browser tests.
   URLRequestContextFactory* const url_request_context_factory_;
-  scoped_ptr<::media::AudioManagerFactory> audio_manager_factory_;
   scoped_ptr<net::NetLog> net_log_;
 
   DISALLOW_COPY_AND_ASSIGN(CastBrowserMainParts);