Extract CdmManager from MojoCdmService.

media/BUILD.gn

Index: media/BUILD.gn
diff --git a/media/BUILD.gn b/media/BUILD.gn
index 8d97ec513ba2e43f871c4a10b1db5d90b40fb9c7..1b704025b11b7482d093ae34473a799fc06be837 100644
--- a/media/BUILD.gn
+++ b/media/BUILD.gn
@@ -377,10 +377,10 @@ component("media") {
   }
 
   if (disable_ffmpeg_video_decoders) {
-      sources -= [
-        "filters/decrypting_video_decoder.cc",
-        "filters/decrypting_video_decoder.h",
-      ]
+    sources -= [
+      "filters/decrypting_video_decoder.cc",
+      "filters/decrypting_video_decoder.h",
+    ]
   }
 
   if (is_android) {
@@ -516,6 +516,27 @@ component("media") {
   }
 }
 
+# Must not be a source_set() because CdmManager exposes a static singleton,
+# shared by multiple component()s.
+component("cdm_manager") {
+  # Because we share :media_implementation, no other targets depending on
+  # :media_implementation can depend on us. To fix that, create a separate
+  # cdm_manager_export.h, with its own independent config.

[xhwang, 2017/05/04 21:06:31]

But we are already depending on ":media" which also uses "media_implementation.
For example, we include media/base/content_decryption_module.h, which uses
MEDIA_EXPORT...

[sandersd (OOO until July 31), 2017/05/04 21:17:47]

Done.

+  visibility = [
+    "//media/gpu",
+    "//media/mojo/services:lib",
+  ]
+  sources = [
+    "cdm/cdm_manager.cc",
+    "cdm/cdm_manager.h",
+  ]
+  configs += [ ":media_implementation" ]
+  deps = [
+    ":media",
+    "//base",
+  ]
+}
+
 static_library("cdm_paths") {
   sources = [
     "cdm/cdm_paths.cc",
@@ -659,9 +680,7 @@ source_set("unit_tests") {
     ]
 
     if (!disable_ffmpeg_video_decoders) {
-      sources += [
-        "filters/ffmpeg_video_decoder_unittest.cc",
-      ]
+      sources += [ "filters/ffmpeg_video_decoder_unittest.cc" ]
     }
   }