Bug 1317759. Remove LegacyIsCallerChromeOrNativeCode use in Event::GetScreenCoords in favor or caller type checks at the entrypoints where we really care about pretending that our screen is client-area sized. r=smaug

dom/events/Event.cpp

@@ -893,12 +893,6 @@ Event::GetScreenCoords(nsPresContext* aPresContext,
                        WidgetEvent* aEvent,
                        LayoutDeviceIntPoint aPoint)
 {
-  if (!nsContentUtils::LegacyIsCallerChromeOrNativeCode() &&
-      nsContentUtils::ResistFingerprinting()) {
-    // When resisting fingerprinting, return client coordinates instead.
-    return GetClientCoords(aPresContext, aEvent, aPoint, CSSIntPoint(0, 0));
-  }
-
   if (EventStateManager::sIsPointerLocked) {
     return EventStateManager::sLastScreenPoint;
   }

dom/events/MouseEvent.cpp

@@ -357,13 +357,21 @@ NS_IMETHODIMP
 MouseEvent::GetScreenX(int32_t* aScreenX)
 {
   NS_ENSURE_ARG_POINTER(aScreenX);
-  *aScreenX = ScreenX();
+  *aScreenX = ScreenX(CallerType::System);
   return NS_OK;
 }
 
 int32_t
-MouseEvent::ScreenX()
+MouseEvent::ScreenX(CallerType aCallerType)
 {
+  if (aCallerType != CallerType::System &&
+      nsContentUtils::ResistFingerprinting()) {
+    // Sanitize to something sort of like client cooords, but not quite
+    // (defaulting to (0,0) instead of our pre-specified client coords).
+    return Event::GetClientCoords(mPresContext, mEvent, mEvent->mRefPoint,
+                                  CSSIntPoint(0, 0)).x;
+  }
+
   return Event::GetScreenCoords(mPresContext, mEvent, mEvent->mRefPoint).x;
 }
 
@@ -371,13 +379,21 @@ NS_IMETHODIMP
 MouseEvent::GetScreenY(int32_t* aScreenY)
 {
   NS_ENSURE_ARG_POINTER(aScreenY);
-  *aScreenY = ScreenY();
+  *aScreenY = ScreenY(CallerType::System);
   return NS_OK;
 }
 
 int32_t
-MouseEvent::ScreenY()
+MouseEvent::ScreenY(CallerType aCallerType)
 {
+  if (aCallerType != CallerType::System &&
+      nsContentUtils::ResistFingerprinting()) {
+    // Sanitize to something sort of like client cooords, but not quite
+    // (defaulting to (0,0) instead of our pre-specified client coords).
+    return Event::GetClientCoords(mPresContext, mEvent, mEvent->mRefPoint,
+                                  CSSIntPoint(0, 0)).y;
+  }
+
   return Event::GetScreenCoords(mPresContext, mEvent, mEvent->mRefPoint).y;
 }
 

dom/events/MouseEvent.h

@@ -7,6 +7,7 @@
 #ifndef mozilla_dom_MouseEvent_h_
 #define mozilla_dom_MouseEvent_h_
 
+#include "mozilla/dom/BindingDeclarations.h"
 #include "mozilla/dom/UIEvent.h"
 #include "mozilla/dom/MouseEventBinding.h"
 #include "mozilla/EventForwards.h"
@@ -42,8 +43,8 @@ public:
     return Button() + 1;
   }
 
-  int32_t ScreenX();
-  int32_t ScreenY();
+  int32_t ScreenX(CallerType aCallerType);
+  int32_t ScreenY(CallerType aCallerType);
   int32_t ClientX();
   int32_t ClientY();
   int32_t OffsetX();

dom/events/Touch.cpp

@@ -140,6 +140,28 @@ Touch::GetTarget() const
   return mTarget;
 }
 
+int32_t
+Touch::ScreenX(CallerType aCallerType) const
+{
+  if (aCallerType != CallerType::System &&
+      nsContentUtils::ResistFingerprinting()) {
+    return ClientX();
+  }
+
+  return mScreenPoint.x;
+}
+
+int32_t
+Touch::ScreenY(CallerType aCallerType) const
+{
+  if (aCallerType != CallerType::System &&
+      nsContentUtils::ResistFingerprinting()) {
+    return ClientY();
+  }
+
+  return mScreenPoint.y;
+}
+
 void
 Touch::InitializePoints(nsPresContext* aPresContext, WidgetEvent* aEvent)
 {

dom/events/Touch.h

@@ -10,6 +10,7 @@
 #include "mozilla/Attributes.h"
 #include "mozilla/EventForwards.h"
 #include "mozilla/MouseEvents.h"
+#include "mozilla/dom/BindingDeclarations.h"
 #include "mozilla/dom/TouchBinding.h"
 #include "nsWrapperCache.h"
 #include "Units.h"
@@ -67,8 +68,8 @@ public:
   // WebIDL
   int32_t Identifier() const { return mIdentifier; }
   EventTarget* GetTarget() const;
-  int32_t ScreenX() const { return mScreenPoint.x; }
-  int32_t ScreenY() const { return mScreenPoint.y; }
+  int32_t ScreenX(CallerType aCallerType) const;
+  int32_t ScreenY(CallerType aCallerType) const;
   int32_t ClientX() const { return mClientPoint.x; }
   int32_t ClientY() const { return mClientPoint.y; }
   int32_t PageX() const { return mPagePoint.x; }

dom/webidl/MouseEvent.webidl

@@ -12,7 +12,9 @@
 
 [Constructor(DOMString typeArg, optional MouseEventInit mouseEventInitDict)]
 interface MouseEvent : UIEvent {
+  [NeedsCallerType]
   readonly attribute long           screenX;
+  [NeedsCallerType]
   readonly attribute long           screenY;
   readonly attribute long           clientX;
   readonly attribute long           clientY;

dom/webidl/Touch.webidl

@@ -30,7 +30,9 @@ dictionary TouchInit {
 interface Touch {
   readonly    attribute long         identifier;
   readonly    attribute EventTarget? target;
+  [NeedsCallerType]
   readonly    attribute long         screenX;
+  [NeedsCallerType]
   readonly    attribute long         screenY;
   readonly    attribute long         clientX;
   readonly    attribute long         clientY;