Revert of Break peerconnection_jni.cc into multiple files, in "pc" directory.

webrtc/sdk/android/src/jni/androidmediacodeccommon.h

Index: webrtc/sdk/android/src/jni/androidmediacodeccommon.h
diff --git a/webrtc/sdk/android/src/jni/androidmediacodeccommon.h b/webrtc/sdk/android/src/jni/androidmediacodeccommon.h
index 9aa97a06bb3c059e762c4133bf0d332075f2e688..fc85f7e9c5160fcda028583686956b19f28d3a7a 100644
--- a/webrtc/sdk/android/src/jni/androidmediacodeccommon.h
+++ b/webrtc/sdk/android/src/jni/androidmediacodeccommon.h
@@ -70,6 +70,15 @@
     current_thread->SetAllowBlockingCalls(true);
 }
 
+// Return the (singleton) Java Enum object corresponding to |index|;
+// |state_class_fragment| is something like "MediaSource$State".
+static inline jobject JavaEnumFromIndexAndClassName(
+    JNIEnv* jni, const std::string& state_class_fragment, int index) {
+  const std::string state_class = "org/webrtc/" + state_class_fragment;
+  return JavaEnumFromIndex(jni, FindClass(jni, state_class.c_str()),
+                           state_class, index);
+}
+
 // Checks for any Java exception, prints stack backtrace and clears
 // currently thrown exception.
 static inline bool CheckException(JNIEnv* jni) {