Componentize EncryptedMediaMessageFilter and rename it CdmMessageFilter.

content/public/renderer/key_system_info.cc

Index: content/public/renderer/key_system_info.cc
diff --git a/content/public/renderer/key_system_info.cc b/content/public/renderer/key_system_info.cc
index 6a64fdbac0049ea49227ab981400a1d28aea8aad..d26c78a7724ae01e354cec76771d0fe75348d427 100644
--- a/content/public/renderer/key_system_info.cc
+++ b/content/public/renderer/key_system_info.cc
@@ -4,8 +4,47 @@
 
 #include "content/public/renderer/key_system_info.h"
 
+#include "base/logging.h"
+
 namespace content {
 
+namespace {
+
+// Return |name|'s parent key system.
+std::string GetDirectParentName(std::string name) {
+  int last_period = name.find_last_of('.');
+  DCHECK_GT(last_period, 0);
+  return name.substr(0, last_period);
+}
+
+}  // namespace
+
+// static
+KeySystemInfo KeySystemInfo::Build(const char* key_system,
+                                   bool has_parent,
+                                   const char* suffix,
+#if defined(ENABLE_PEPPER_CDMS)
+                                   const char* pepper_type,
+#endif  // defined(ENABLE_PEPPER_CDMS)
+                                   SupportedCodecs supported_codecs) {
+  KeySystemInfo info(key_system);
+
+  if (has_parent)
+    info.parent_key_system = GetDirectParentName(key_system);
+  if (suffix)
+    info.key_system.append(suffix);
+
+  // TODO(xhwang): A container or an initDataType may be supported even though
+  // there are no codecs supported in that container. Fix this when we support
+  // initDataType.
+  info.supported_codecs = supported_codecs;
+
+#if defined(ENABLE_PEPPER_CDMS)
+  info.pepper_type = pepper_type;
+#endif  // defined(ENABLE_PEPPER_CDMS)
+  return info;
+}
+
 KeySystemInfo::KeySystemInfo(const std::string& key_system)
     : key_system(key_system),
       use_aes_decryptor(false) {