--- a/js/xpconnect/src/XPCJSRuntime.cpp
+++ b/js/xpconnect/src/XPCJSRuntime.cpp
@@ -2896,37 +2896,34 @@ static nsresult ReadSourceFromFilename(J
     rv = scriptStream->Read(ptr, PointerRangeSize(ptr, end), &bytesRead);
     if (NS_FAILED(rv)) {
       return rv;
     }
     MOZ_ASSERT(bytesRead > 0, "stream promised more bytes before EOF");
     ptr += bytesRead;
   }
 
-  size_t bytesAllocated;
   if (utf8Source) {
     // |buf| is already UTF-8, so we can directly return it.
-    *len = bytesAllocated = rawLen;
+    *len = rawLen;
     *utf8Source = buf.release();
   } else {
     MOZ_ASSERT(twoByteSource != nullptr);
 
     // |buf| can't be directly returned -- convert it to UTF-16.
 
     // On success this overwrites |*twoByteSource| and |*len|.
     rv = ScriptLoader::ConvertToUTF16(
         scriptChannel, reinterpret_cast<const unsigned char*>(buf.get()),
         rawLen, NS_LITERAL_STRING("UTF-8"), nullptr, *twoByteSource, *len);
     NS_ENSURE_SUCCESS(rv, rv);
 
     if (!*twoByteSource) {
       return NS_ERROR_FAILURE;
     }
-
-    bytesAllocated = *len * sizeof(char16_t);
   }
 
   return NS_OK;
 }
 
 // The JS engine calls this object's 'load' member function when it needs
 // the source for a chrome JS function. See the comment in the XPCJSRuntime
 // constructor.
@@ -3018,17 +3015,17 @@ js::UniquePtr<EdgeRange> ReflectorNode::
     return nullptr;
   }
   // UNWRAP_NON_WRAPPER_OBJECT assumes the object is completely initialized,
   // but ours may not be. Luckily, UnwrapDOMObjectToISupports checks for the
   // uninitialized case (and returns null if uninitialized), so we can use that
   // to guard against uninitialized objects.
   nsISupports* supp = UnwrapDOMObjectToISupports(&get());
   if (supp) {
-    JS::AutoSuppressGCAnalysis nogc; // bug 1582326
+    JS::AutoSuppressGCAnalysis nogc;  // bug 1582326
 
     nsINode* node;
     // UnwrapDOMObjectToISupports can only return non-null if its argument is
     // an actual DOM object, not a cross-compartment wrapper.
     if (NS_SUCCEEDED(UNWRAP_NON_WRAPPER_OBJECT(Node, &get(), node))) {
       char16_t* edgeName = nullptr;
       if (wantNames) {
         edgeName = NS_xstrdup(u"Reflected Node");
@@ -3279,36 +3276,36 @@ JSObject* XPCJSRuntime::GetUAWidgetScope
   MOZ_ASSERT(!nsContentUtils::IsSystemPrincipal(principal),
              "Running UA Widget in chrome");
 
   RootedObject scope(cx);
   do {
     RefPtr<BasePrincipal> key = BasePrincipal::Cast(principal);
     if (Principal2JSObjectMap::Ptr p = mUAWidgetScopeMap.lookup(key)) {
       scope = p->value();
-      break; // Need ~RefPtr to run, and potentially GC, before returning.
+      break;  // Need ~RefPtr to run, and potentially GC, before returning.
     }
 
     SandboxOptions options;
     options.sandboxName.AssignLiteral("UA Widget Scope");
     options.wantXrays = false;
     options.wantComponents = false;
     options.isUAWidgetScope = true;
 
     // Use an ExpandedPrincipal to create asymmetric security.
     MOZ_ASSERT(!nsContentUtils::IsExpandedPrincipal(principal));
     nsTArray<nsCOMPtr<nsIPrincipal>> principalAsArray(1);
     principalAsArray.AppendElement(principal);
     RefPtr<ExpandedPrincipal> ep = ExpandedPrincipal::Create(
-      principalAsArray, principal->OriginAttributesRef());
+        principalAsArray, principal->OriginAttributesRef());
 
     // Create the sandbox.
     RootedValue v(cx);
     nsresult rv = CreateSandboxObject(
-      cx, &v, static_cast<nsIExpandedPrincipal*>(ep), options);
+        cx, &v, static_cast<nsIExpandedPrincipal*>(ep), options);
     NS_ENSURE_SUCCESS(rv, nullptr);
     scope = &v.toObject();
 
     MOZ_ASSERT(xpc::IsInUAWidgetScope(js::UncheckedUnwrap(scope)));
 
     MOZ_ALWAYS_TRUE(mUAWidgetScopeMap.putNew(key, scope));
   } while (false);