adding const to variable to comply with google code convention...

may need to change more stuff though. Taint what else do you mean? Spaces, tabs, names?

src/allreduce.h

@@ -47,7 +47,7 @@ void Finalize(void) {
   engine::Finalize();
 }
 #ifdef TEST
-void SetMock(test::Mock& mock) {
+void SetMock(const test::Mock& mock) {
   engine::SetMock(mock);
 }
 #endif

src/engine.h

@@ -82,7 +82,7 @@ void Finalize(void);
 IEngine *GetEngine(void);
 
 #ifdef TEST
-void SetMock(test::Mock& mock);
+void SetMock(const test::Mock& mock);
 #endif
 
 }  // namespace engine

src/engine_tcp.cpp

@@ -42,7 +42,7 @@ class SyncManager : public IEngine {
   }
 
   #ifdef TEST
-  inline void SetMock(test::Mock& mock) {
+  inline void SetMock(const test::Mock& mock) {
     this->mock = mock;
   }
   #endif
@@ -501,7 +501,7 @@ void Init(int argc, char *argv[]) {
 
 #ifdef TEST
 /*! \brief sets a mock to the manager for testing purposes */
-void SetMock(test::Mock& mock) {
+void SetMock(const test::Mock& mock) {
   manager.SetMock(mock);
 }
 #endif