Add trace code to system server.

- Add TRACE_TAG_SYSTEM_SERVER for tracing system server code.
- Add a few more tracing code to the code paths related to boot.

BUG: 21739901
BUG: 22207144
Change-Id: I08b424d2f83783f512c3818394099909cd55f327
diff --git a/core/jni/AndroidRuntime.cpp b/core/jni/AndroidRuntime.cpp
index 7e7b74a..1cbbeff 100644
--- a/core/jni/AndroidRuntime.cpp
+++ b/core/jni/AndroidRuntime.cpp
@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+#define ATRACE_TAG ATRACE_TAG_DALVIK
 #define LOG_TAG "AndroidRuntime"
 //#define LOG_NDEBUG 0
 
@@ -23,6 +24,7 @@
 #include <binder/IServiceManager.h>
 #include <utils/Log.h>
 #include <utils/misc.h>
+#include <utils/Trace.h>
 #include <binder/Parcel.h>
 #include <utils/threads.h>
 #include <cutils/properties.h>
@@ -1400,6 +1402,7 @@
  */
 /*static*/ int AndroidRuntime::startReg(JNIEnv* env)
 {
+    ATRACE_NAME("RegisterAndroidNatives");
     /*
      * This hook causes all future threads created in this process to be
      * attached to the JavaVM.  (This needs to go away in favor of JNI