Rename the various shell MojoMains to ShellMain.

shell/android/main.h

Index: shell/android/main.h
diff --git a/shell/android/main.h b/shell/android/main.h
index bc2e9f18a5176e365fb0462c8b9299c2e342fa39..43ea16aa344128e29920cabeeb1ed14d7918b4fa 100644
--- a/shell/android/main.h
+++ b/shell/android/main.h
@@ -2,17 +2,17 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef SHELL_ANDROID_MOJO_MAIN_H_
-#define SHELL_ANDROID_MOJO_MAIN_H_
+#ifndef SHELL_ANDROID_MAIN_H_
+#define SHELL_ANDROID_MAIN_H_
 
 #include <jni.h>
 
 namespace mojo {
 namespace shell {
 
-bool RegisterMojoMain(JNIEnv* env);
+bool RegisterShellMain(JNIEnv* env);
 
 }  // namespace shell
 }  // namespace mojo
 
-#endif  // SHELL_ANDROID_MOJO_MAIN_H_
+#endif  // SHELL_ANDROID_MAIN_H_