Generate all extension schema namespaces as "api" and instead vary the generated bundle names.

extensions/browser/api/cast_channel/cast_socket_unittest.cc

Index: extensions/browser/api/cast_channel/cast_socket_unittest.cc
diff --git a/extensions/browser/api/cast_channel/cast_socket_unittest.cc b/extensions/browser/api/cast_channel/cast_socket_unittest.cc
index 274fb6b20ca5f3eccfa5f719756d61b41ef1b3fb..464cb38f4ae6a7ab4bf26550cf252798e5702b2a 100644
--- a/extensions/browser/api/cast_channel/cast_socket_unittest.cc
+++ b/extensions/browser/api/cast_channel/cast_socket_unittest.cc
@@ -43,7 +43,7 @@ using ::testing::Return;
 using ::testing::SaveArg;
 
 namespace extensions {
-namespace core_api {
+namespace api {
 namespace cast_channel {
 const char kAuthNamespace[] = "urn:x-cast:com.google.cast.tp.deviceauth";
 
@@ -946,5 +946,5 @@ TEST_F(CastSocketTest, TestChannelPolicyVerificationCapabilitiesVideoOut) {
   EXPECT_FALSE(socket_->TestVerifyChannelPolicyAudioOnly());
 }
 }  // namespace cast_channel
-}  // namespace core_api
+}  // namespace api
 }  // namespace extensions