--- a/dom/html/HTMLButtonElement.cpp
+++ b/dom/html/HTMLButtonElement.cpp
@@ -364,17 +364,17 @@ HTMLButtonElement::PostHandleEvent(Event
       default:
         break;
     }
     if (aVisitor.mItemFlags & NS_OUTER_ACTIVATE_EVENT) {
       if (mForm && (mType == NS_FORM_BUTTON_SUBMIT ||
                     mType == NS_FORM_BUTTON_RESET)) {
         InternalFormEvent event(true,
           (mType == NS_FORM_BUTTON_RESET) ? eFormReset : eFormSubmit);
-        event.originator     = this;
+        event.mOriginator = this;
         nsEventStatus status = nsEventStatus_eIgnore;
 
         nsCOMPtr<nsIPresShell> presShell =
           aVisitor.mPresContext->GetPresShell();
         // If |nsIPresShell::Destroy| has been called due to
         // handling the event, the pres context will return
         // a null pres shell.  See bug 125624.
         //

--- a/dom/html/HTMLFormElement.cpp
+++ b/dom/html/HTMLFormElement.cpp
@@ -682,17 +682,17 @@ HTMLFormElement::BuildSubmission(HTMLFor
 {
   NS_ASSERTION(!mPendingSubmission, "tried to build two submissions!");
 
   // Get the originating frame (failure is non-fatal)
   nsGenericHTMLElement* originatingElement = nullptr;
   if (aEvent) {
     InternalFormEvent* formEvent = aEvent->AsFormEvent();
     if (formEvent) {
-      nsIContent* originator = formEvent->originator;
+      nsIContent* originator = formEvent->mOriginator;
       if (originator) {
         if (!originator->IsHTMLElement()) {
           return NS_ERROR_UNEXPECTED;
         }
         originatingElement = static_cast<nsGenericHTMLElement*>(originator);
       }
     }
   }

--- a/dom/html/HTMLInputElement.cpp
+++ b/dom/html/HTMLInputElement.cpp
@@ -4552,17 +4552,17 @@ HTMLInputElement::PostHandleEvent(EventC
         }
         switch(mType) {
         case NS_FORM_INPUT_RESET:
         case NS_FORM_INPUT_SUBMIT:
         case NS_FORM_INPUT_IMAGE:
           if (mForm) {
             InternalFormEvent event(true,
               (mType == NS_FORM_INPUT_RESET) ? eFormReset : eFormSubmit);
-            event.originator      = this;
+            event.mOriginator = this;
             nsEventStatus status  = nsEventStatus_eIgnore;
 
             nsCOMPtr<nsIPresShell> presShell =
               aVisitor.mPresContext->GetPresShell();
 
             // If |nsIPresShell::Destroy| has been called due to
             // handling the event the pres context will return a null
             // pres shell.  See bug 125624.

--- a/widget/ContentEvents.h
+++ b/widget/ContentEvents.h
@@ -108,47 +108,47 @@ public:
     mArea = aEvent.mArea;
   }
 };
 
 /******************************************************************************
  * mozilla::InternalFormEvent
  *
  * We hold the originating form control for form submit and reset events.
- * originator is a weak pointer (does not hold a strong reference).
+ * mOriginator is a weak pointer (does not hold a strong reference).
  ******************************************************************************/
 
 class InternalFormEvent : public WidgetEvent
 {
 public:
   virtual InternalFormEvent* AsFormEvent() override { return this; }
 
   InternalFormEvent(bool aIsTrusted, EventMessage aMessage)
     : WidgetEvent(aIsTrusted, aMessage, eFormEventClass)
-    , originator(nullptr)
+    , mOriginator(nullptr)
   {
   }
 
   virtual WidgetEvent* Duplicate() const override
   {
     MOZ_ASSERT(mClass == eFormEventClass,
                "Duplicate() must be overridden by sub class");
     InternalFormEvent* result = new InternalFormEvent(false, mMessage);
     result->AssignFormEventData(*this, true);
     result->mFlags = mFlags;
     return result;
   }
 
-  nsIContent *originator;
+  nsIContent* mOriginator;
 
   void AssignFormEventData(const InternalFormEvent& aEvent, bool aCopyTargets)
   {
     AssignEventData(aEvent, aCopyTargets);
 
-    // Don't copy originator due to a weak pointer.
+    // Don't copy mOriginator due to a weak pointer.
   }
 };
 
 /******************************************************************************
  * mozilla::InternalClipboardEvent
  ******************************************************************************/
 
 class InternalClipboardEvent : public WidgetEvent