Add Cronet Test App that uses libcronet_tests.so with net test utilities.

components/cronet/android/cronet_loader.cc

Index: components/cronet/android/cronet_loader.cc
diff --git a/components/cronet/android/cronet_jni.cc b/components/cronet/android/cronet_loader.cc
similarity index 92%
copy from components/cronet/android/cronet_jni.cc
copy to components/cronet/android/cronet_loader.cc
index 7ebd14131469e7035f7f10c2e1426c3d13133063..197a2eade57c8b05a8a6b5e9cc8970e8d3b540e5 100644
--- a/components/cronet/android/cronet_jni.cc
+++ b/components/cronet/android/cronet_loader.cc
@@ -16,6 +16,7 @@
 #include "base/i18n/icu_util.h"
 #endif
 
+namespace cronet {
 namespace {
 
 const base::android::RegistrationMethod kCronetRegisteredMethods[] = {
@@ -31,7 +32,7 @@ base::AtExitManager* g_at_exit_manager = NULL;
 }  // namespace
 
 // Checks the available version of JNI. Also, caches Java reflection artifacts.
-extern "C" jint JNI_OnLoad(JavaVM* vm, void* reserved) {
+jint CronetOnLoad(JavaVM* vm, void* reserved) {
   JNIEnv* env;
   if (vm->GetEnv(reinterpret_cast<void**>(&env), JNI_VERSION_1_6) != JNI_OK) {
     return -1;
@@ -55,10 +56,11 @@ extern "C" jint JNI_OnLoad(JavaVM* vm, void* reserved) {
   return JNI_VERSION_1_6;
 }
 
-extern "C" void JNIEXPORT JNICALL JNI_OnUnLoad(JavaVM* jvm, void* reserved) {
+void CronetOnUnLoad(JavaVM* jvm, void* reserved) {
   if (g_at_exit_manager) {
     delete g_at_exit_manager;
     g_at_exit_manager = NULL;
   }
 }
 
+}  // namespace cronet