Fix clang build

mojo/services/native_viewport/android/mojo_viewport.cc

Index: mojo/services/native_viewport/android/mojo_viewport.cc
diff --git a/mojo/services/native_viewport/android/mojo_viewport.cc b/mojo/services/native_viewport/android/mojo_viewport.cc
index 97357da18f77833e87dfeba13a90a64b4c9a30e7..39615669d9ff2285b355031f6b706f2cfa2ead21 100644
--- a/mojo/services/native_viewport/android/mojo_viewport.cc
+++ b/mojo/services/native_viewport/android/mojo_viewport.cc
@@ -14,6 +14,12 @@
 namespace mojo {
 namespace services {
 
+MojoViewportInit::MojoViewportInit() {
+}
+
+MojoViewportInit::~MojoViewportInit() {
+}
+
 static jint Init(JNIEnv* env, jclass obj, jint jinit) {
   MojoViewportInit* init = reinterpret_cast<MojoViewportInit*>(jinit);
   MojoViewport* viewport = new MojoViewport(init);