Bug 1442599 - Part 1: Replace AutoScopedAssign with MakeScopeExit. r=jorendorff

--HG--
extra : rebase_source : 15f362a6976aedea503a983f14acfc6c626914f8

js/src/jsexn.cpp

@@ -10,6 +10,7 @@
 
 #include "jsexn.h"
 
+#include "mozilla/ScopeExit.h"
 #include "mozilla/Sprintf.h"
 
 #include <string.h>
@@ -667,7 +668,11 @@ js::ErrorToException(JSContext* cx, JSErrorReport* reportp,
     // Prevent infinite recursion.
     if (cx->generatingError)
         return;
-    AutoScopedAssign<bool> asa(&cx->generatingError.ref(), true);
+
+    cx->generatingError = true;
+    auto restore = mozilla::MakeScopeExit([cx] {
+        cx->generatingError = false;
+    });
 
     // Create an exception object.
     RootedString messageStr(cx, reportp->newMessageString(cx));

js/src/jsutil.h

@@ -13,7 +13,6 @@
 
 #include "mozilla/Assertions.h"
 #include "mozilla/Compiler.h"
-#include "mozilla/GuardObjects.h"
 #include "mozilla/HashFunctions.h"
 #include "mozilla/MathAlgorithms.h"
 #include "mozilla/PodOperations.h"
@@ -156,26 +155,6 @@ Max(T t1, T t2)
     return t1 > t2 ? t1 : t2;
 }
 
-template<typename T>
-class MOZ_RAII AutoScopedAssign
-{
-  public:
-    AutoScopedAssign(T* addr, const T& value
-                     MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
-        : addr_(addr), old(*addr_)
-    {
-        MOZ_GUARD_OBJECT_NOTIFIER_INIT;
-        *addr_ = value;
-    }
-
-    ~AutoScopedAssign() { *addr_ = old; }
-
-  private:
-    MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
-    T* addr_;
-    T old;
-};
-
 template <typename T, typename U>
 static inline U
 ComputeByteAlignment(T bytes, U alignment)