Move runner stuff into a runner namespace.

mojo/runner/android/android_handler.h

Index: mojo/runner/android/android_handler.h
diff --git a/mojo/runner/android/android_handler.h b/mojo/runner/android/android_handler.h
index e36ff6d2824d999fb3a57dd264432b5ad6feeb37..ad0e89729d306d69f840eaf285ba356c5966d0e5 100644
--- a/mojo/runner/android/android_handler.h
+++ b/mojo/runner/android/android_handler.h
@@ -17,7 +17,7 @@ class FilePath;
 }
 
 namespace mojo {
-namespace shell {
+namespace runner {
 
 class AndroidHandler : public ApplicationDelegate,
                        public ContentHandlerFactory::Delegate {
@@ -40,7 +40,7 @@ class AndroidHandler : public ApplicationDelegate,
 
 bool RegisterAndroidHandlerJni(JNIEnv* env);
 
-}  // namespace shell
+}  // namespace runner
 }  // namespace mojo
 
 #endif  // MOJO_RUNNER_ANDROID_ANDROID_HANDLER_H_