Bug 1403694: Fix a case where a NULL stylesheet would be added to the nsStyleSheetService if nsLayoutUtils::StyloSupportedInCurrentProcess() returns false. r=xidorn

MozReview-Commit-ID: COaDbr49B7B

--HG--
extra : rebase_source : c4cb37f2f57444af41eccfb93d0e73895e4ae7b8

layout/base/nsStyleSheetService.cpp

@@ -251,23 +251,23 @@ nsStyleSheetService::LoadAndRegisterSheetInternal(nsIURI *aSheetURI,
   nsresult rv;
 
   RefPtr<StyleSheet> geckoSheet;
-  RefPtr<StyleSheet> servoSheet;
 
   rv = LoadSheet(aSheetURI, parsingMode, StyleBackendType::Gecko, &geckoSheet);
   NS_ENSURE_SUCCESS(rv, rv);
   MOZ_ASSERT(geckoSheet);
+  mGeckoSheets[aSheetType].AppendElement(geckoSheet);
 
 #ifdef MOZ_STYLO
   if (nsLayoutUtils::StyloSupportedInCurrentProcess()) {
+    RefPtr<StyleSheet> servoSheet;
+
     rv = LoadSheet(aSheetURI, parsingMode, StyleBackendType::Servo, &servoSheet);
     NS_ENSURE_SUCCESS(rv, rv);
     MOZ_ASSERT(servoSheet);
+    mServoSheets[aSheetType].AppendElement(servoSheet);
   }
 #endif
 
-  mGeckoSheets[aSheetType].AppendElement(geckoSheet);
-  mServoSheets[aSheetType].AppendElement(servoSheet);
-
   return NS_OK;
 }