Extract requestMediaKeySystemAccess() algorithm.

media/base/key_systems_unittest.cc

Index: media/base/key_systems_unittest.cc
diff --git a/media/base/key_systems_unittest.cc b/media/base/key_systems_unittest.cc
index f26f69436a1e12689df6774c1488c701de660233..b80e6a1e9d2b8ac74be7dfa9a0745c87219043be 100644
--- a/media/base/key_systems_unittest.cc
+++ b/media/base/key_systems_unittest.cc
@@ -77,7 +77,7 @@ static bool IsSupportedKeySystemWithMediaMimeType(
     const std::string& mime_type,
     const std::vector<std::string>& codecs,
     const std::string& key_system) {
-  return KeySystems::GetInstance().IsSupportedCodecCombination(
+  return KeySystems::GetInstance()->IsSupportedCodecCombination(
       key_system, EmeMediaType::VIDEO, mime_type, codecs);
 }
 
@@ -85,7 +85,7 @@ static bool IsSupportedKeySystemWithAudioMimeType(
     const std::string& mime_type,
     const std::vector<std::string>& codecs,
     const std::string& key_system) {
-  return KeySystems::GetInstance().IsSupportedCodecCombination(
+  return KeySystems::GetInstance()->IsSupportedCodecCombination(
       key_system, EmeMediaType::AUDIO, mime_type, codecs);
 }