Bug 1068022 - Fix more bad implicit constructors in gfx; r=jrmuizel

gfx/layers/apz/src/AsyncPanZoomController.cpp

@@ -410,7 +410,7 @@ GetFrameTime() {
 
 class MOZ_STACK_CLASS StateChangeNotificationBlocker {
 public:
-  StateChangeNotificationBlocker(AsyncPanZoomController* aApzc)
+  explicit StateChangeNotificationBlocker(AsyncPanZoomController* aApzc)
     : mApzc(aApzc)
   {
     ReentrantMonitorAutoEnter lock(mApzc->mMonitor);

gfx/layers/ipc/ThreadSafeRefcountingWithMainThreadDestruction.h

@@ -41,7 +41,7 @@ template<typename T>
 struct DeleteOnMainThreadTask: public nsRunnable
 {
   T* mToDelete;
-  DeleteOnMainThreadTask(T* aToDelete) : mToDelete(aToDelete) {}
+  explicit DeleteOnMainThreadTask(T* aToDelete) : mToDelete(aToDelete) {}
   NS_IMETHOD Run() {
     MOZ_ASSERT(NS_IsMainThread());
     mToDelete->DeleteToBeCalledOnMainThread();
@@ -87,4 +87,4 @@ private:                                                                      \
   ::mozilla::layers::HelperForMainThreadDestruction mHelperForMainThreadDestruction; \
 public:
 
-#endif
+#endif