media: Replace DecryptorReadyCB with CdmReadyCB.

media/base/cdm_context.h

Index: media/base/cdm_context.h
diff --git a/media/base/cdm_context.h b/media/base/cdm_context.h
index 7d897608cc39946e513334ca6a0a55cc1ee19e5a..c64f276efd00720a8f77da537f64aa5036b67dd7 100644
--- a/media/base/cdm_context.h
+++ b/media/base/cdm_context.h
@@ -68,6 +68,19 @@ typedef base::Callback<void(bool)> CdmAttachedCB;
 // A dummy implementation of CdmAttachedCB.
 MEDIA_EXPORT void IgnoreCdmAttached(bool success);
 
+// Callback to notify that a CDM is ready. CdmAttachedCB is called when the CDM
+// has been completely attached to the media pipeline.
+typedef base::Callback<void(CdmContext*, const CdmAttachedCB&)> CdmReadyCB;
+
+// Callback to set/cancel a CdmReadyCB.
+// Calling this callback with a non-null callback registers CDM ready
+// notification. When the CDM is ready, notification will be sent
+// through the provided callback.
+// Calling this callback with a null callback cancels previously registered CDM
+// ready notification. Any previously provided callback will be fired
+// immediately with NULL.
+typedef base::Callback<void(const CdmReadyCB&)> SetCdmReadyCB;
+
 }  // namespace media
 
 #endif  // MEDIA_BASE_CDM_CONTEXT_H_