Bug 1320801 part 5. Switch from ShouldResistFingerprinting to ResistFingerprinting (use the caller type, not the document principal) in nsGlobalWindow's devicePixelRatio getter. r=bkelly

dom/base/nsDOMWindowUtils.cpp

@@ -18,6 +18,7 @@
 #include "nsFocusManager.h"
 #include "nsFrameManager.h"
 #include "nsRefreshDriver.h"
+#include "mozilla/dom/BindingDeclarations.h"
 #include "mozilla/dom/BlobBinding.h"
 #include "mozilla/dom/Touch.h"
 #include "mozilla/PendingAnimationTracker.h"
@@ -1848,7 +1849,8 @@ nsDOMWindowUtils::GetScreenPixelsPerCSSPixel(float* aScreenPixels)
 {
   nsCOMPtr<nsPIDOMWindowOuter> window = do_QueryReferent(mWindow);
   NS_ENSURE_TRUE(window, NS_ERROR_FAILURE);
-  return window->GetDevicePixelRatio(aScreenPixels);
+  *aScreenPixels = window->GetDevicePixelRatio(CallerType::System);
+  return NS_OK;
 }
 
 NS_IMETHODIMP

dom/base/nsGlobalWindow.cpp

@@ -5572,7 +5572,7 @@ nsGlobalWindow::GetMozInnerScreenY(CallerType aCallerType, ErrorResult& aError)
 }
 
 float
-nsGlobalWindow::GetDevicePixelRatioOuter()
+nsGlobalWindow::GetDevicePixelRatioOuter(CallerType aCallerType)
 {
   MOZ_RELEASE_ASSERT(IsOuterWindow());
 
@@ -5586,7 +5586,7 @@ nsGlobalWindow::GetDevicePixelRatioOuter()
     return 1.0;
   }
 
-  if (nsContentUtils::ShouldResistFingerprinting(mDocShell)) {
+  if (nsContentUtils::ResistFingerprinting(aCallerType)) {
     return 1.0;
   }
 
@@ -5601,20 +5601,15 @@ nsGlobalWindow::GetDevicePixelRatioOuter()
 }
 
 float
-nsGlobalWindow::GetDevicePixelRatio(ErrorResult& aError)
+nsGlobalWindow::GetDevicePixelRatio(CallerType aCallerType, ErrorResult& aError)
 {
-  FORWARD_TO_OUTER_OR_THROW(GetDevicePixelRatioOuter, (), aError, 0.0);
+  FORWARD_TO_OUTER_OR_THROW(GetDevicePixelRatioOuter, (aCallerType), aError, 0.0);
 }
 
-nsresult
-nsGlobalWindow::GetDevicePixelRatio(float* aRatio)
+float
+nsPIDOMWindowOuter::GetDevicePixelRatio(CallerType aCallerType)
 {
-  FORWARD_TO_INNER(GetDevicePixelRatio, (aRatio), NS_ERROR_UNEXPECTED);
-
-  ErrorResult rv;
-  *aRatio = GetDevicePixelRatio(rv);
-
-  return rv.StealNSResult();
+  return nsGlobalWindow::Cast(this)->GetDevicePixelRatioOuter(aCallerType);
 }
 
 uint64_t

dom/base/nsGlobalWindow.h

@@ -1118,9 +1118,9 @@ public:
   float GetMozInnerScreenYOuter(mozilla::dom::CallerType aCallerType);
   float GetMozInnerScreenY(mozilla::dom::CallerType aCallerType,
                            mozilla::ErrorResult& aError);
-  float GetDevicePixelRatioOuter();
-  float GetDevicePixelRatio(mozilla::ErrorResult& aError);
-  nsresult GetDevicePixelRatio(float* aRatio) override;
+  float GetDevicePixelRatioOuter(mozilla::dom::CallerType aCallerType);
+  float GetDevicePixelRatio(mozilla::dom::CallerType aCallerType,
+                            mozilla::ErrorResult& aError);
   int32_t GetScrollMinX(mozilla::ErrorResult& aError);
   int32_t GetScrollMinY(mozilla::ErrorResult& aError);
   int32_t GetScrollMaxX(mozilla::ErrorResult& aError);

dom/base/nsPIDOMWindow.h

@@ -51,6 +51,7 @@ class ServiceWorkerRegistration;
 class Timeout;
 class TimeoutManager;
 class CustomElementRegistry;
+enum class CallerType : uint32_t;
 } // namespace dom
 } // namespace mozilla
 
@@ -557,7 +558,6 @@ public:
                               nsISupports* aExtraArgument,
                               nsPIDOMWindowOuter** _retval) = 0;
 
-  virtual nsresult GetDevicePixelRatio(float* aRatio) = 0;
   virtual nsresult GetInnerWidth(int32_t* aWidth) = 0;
   virtual nsresult GetInnerHeight(int32_t* aHeight) = 0;
   virtual already_AddRefed<nsICSSDeclaration>
@@ -936,6 +936,8 @@ public:
 
   void SetServiceWorkersTestingEnabled(bool aEnabled);
   bool GetServiceWorkersTestingEnabled();
+
+  float GetDevicePixelRatio(mozilla::dom::CallerType aCallerType);
 };
 
 NS_DEFINE_STATIC_IID_ACCESSOR(nsPIDOMWindowOuter, NS_PIDOMWINDOWOUTER_IID)

dom/media/webrtc/MediaEngineTabVideoSource.cpp

@@ -8,6 +8,7 @@
 #include "mozilla/gfx/2D.h"
 #include "mozilla/RefPtr.h"
 #include "mozilla/UniquePtrExtensions.h"
+#include "mozilla/dom/BindingDeclarations.h"
 #include "nsGlobalWindow.h"
 #include "nsIDOMClientRect.h"
 #include "nsIDocShell.h"
@@ -284,7 +285,7 @@ MediaEngineTabVideoSource::Draw() {
   {
     float pixelRatio;
     if (mWindow) {
-      mWindow->GetDevicePixelRatio(&pixelRatio);
+      pixelRatio = mWindow->GetDevicePixelRatio(CallerType::System);
     } else {
       pixelRatio = 1.0f;
     }

dom/webidl/Window.webidl

@@ -287,7 +287,8 @@ partial interface Window {
   readonly attribute float mozInnerScreenX;
   [Throws, NeedsCallerType]
   readonly attribute float mozInnerScreenY;
-  [Replaceable, Throws] readonly attribute float  devicePixelRatio;
+  [Replaceable, Throws, NeedsCallerType]
+  readonly attribute float devicePixelRatio;
 
   /* The maximum offset that the window can be scrolled to
      (i.e., the document width/height minus the scrollport width/height) */