media: Add out-of-line copy ctors for complex classes.

media/base/cdm_key_information.cc

Index: media/base/cdm_key_information.cc
diff --git a/media/base/cdm_key_information.cc b/media/base/cdm_key_information.cc
index 70d4464b850fecf594086df6c476dcf8b14d19cb..efaed61f9716e01cbbe266549a3b35effe251d79 100644
--- a/media/base/cdm_key_information.cc
+++ b/media/base/cdm_key_information.cc
@@ -32,6 +32,8 @@ CdmKeyInformation::CdmKeyInformation(const uint8_t* key_id_data,
       status(status),
       system_code(system_code) {}
 
+CdmKeyInformation::CdmKeyInformation(const CdmKeyInformation& other) = default;
+
 CdmKeyInformation::~CdmKeyInformation() {
 }