media: Support creation and SetCdm() for mojo based CDM.

media/mojo/services/BUILD.gn

Index: media/mojo/services/BUILD.gn
diff --git a/media/mojo/services/BUILD.gn b/media/mojo/services/BUILD.gn
index 38adaa7c397660dc3420a867074bc87251247946..59c213626a076ef0c06b6682e62569d429cb4f47 100644
--- a/media/mojo/services/BUILD.gn
+++ b/media/mojo/services/BUILD.gn
@@ -52,6 +52,8 @@ source_set("cdm_proxy") {
   sources = [
     "mojo_cdm.cc",
     "mojo_cdm.h",
+    "mojo_cdm_factory.cc",
+    "mojo_cdm_factory.h",
     "mojo_type_trait.h",
   ]
 }
@@ -69,10 +71,14 @@ source_set("cdm_service") {
   ]
 
   sources = [
+    "mojo_cdm_factory_service.cc",
+    "mojo_cdm_factory_service.h",
     "mojo_cdm_promise.cc",
     "mojo_cdm_promise.h",
     "mojo_cdm_service.cc",
     "mojo_cdm_service.h",
+    "mojo_cdm_service_context.cc",
+    "mojo_cdm_service_context.h",
     "mojo_type_trait.h",
   ]
 
@@ -168,6 +174,7 @@ if (!is_component_build) {
     ]
 
     deps = [
+      ":cdm_service",
       ":renderer_service",
       "//mojo/application/public/cpp",
       "//third_party/mojo/src/mojo/public/c/system:for_shared_library",