Bug 1378983 - Improve the packing of HTMLFormElement; r=mystor

This brings the size of this node to 512 bytes on 64-bit debug builds.

dom/html/HTMLFormElement.cpp

@@ -100,14 +100,6 @@ HTMLFormElement::HTMLFormElement(already_AddRefed<mozilla::dom::NodeInfo>& aNode
     mSelectedRadioButtons(2),
     mRequiredRadioButtonCounts(2),
     mValueMissingRadioGroups(2),
-    mGeneratingSubmit(false),
-    mGeneratingReset(false),
-    mIsSubmitting(false),
-    mDeferSubmission(false),
-    mNotifiedObservers(false),
-    mNotifiedObserversResult(false),
-    mSubmitPopupState(openAbused),
-    mSubmitInitiatedFromUserInput(false),
     mPendingSubmission(nullptr),
     mSubmittingRequest(nullptr),
     mDefaultSubmitElement(nullptr),
@@ -115,7 +107,15 @@ HTMLFormElement::HTMLFormElement(already_AddRefed<mozilla::dom::NodeInfo>& aNode
     mFirstSubmitNotInElements(nullptr),
     mImageNameLookupTable(FORM_CONTROL_LIST_HASHTABLE_LENGTH),
     mPastNameLookupTable(FORM_CONTROL_LIST_HASHTABLE_LENGTH),
+    mSubmitPopupState(openAbused),
     mInvalidElementsCount(0),
+    mGeneratingSubmit(false),
+    mGeneratingReset(false),
+    mIsSubmitting(false),
+    mDeferSubmission(false),
+    mNotifiedObservers(false),
+    mNotifiedObserversResult(false),
+    mSubmitInitiatedFromUserInput(false),
     mEverTriedInvalidSubmit(false)
 {
   // We start out valid.