media: Make MediaKeys ref-counted.

media/base/BUILD.gn

 # Copyright 2014 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.
 
 import("//build/config/android/config.gni")
 import("//build/config/arm.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//build/config/linux/pkg_config.gni")
 import("//media/media_options.gni")
@@ skipping 222 matching lines @@
         "media_file_checker.cc",
         "media_file_checker.h",
       ]
     }
 
     deps += [ "//third_party/ffmpeg" ]
   }
 
   if (enable_browser_cdms) {
     sources += [
-      "browser_cdm.cc",
-      "browser_cdm.h",
       "browser_cdm_factory.cc",
       "browser_cdm_factory.h",
     ]
   }
 
   if (is_android) {
     public_deps = [
       "//media/base/android",
       "//media/base/android:media_java",
       "//media/base/android:media_jni_headers",
@@ skipping 286 matching lines @@
       if (is_posix) {
         yasm_flags += [ "-DELF" ]
         if (current_cpu == "x64") {
           # TODO(ajwong): Why isn't this true in mac?
           yasm_flags += [ "-DPIC" ]
         }
       }
     }
   }
 }