--- a/layout/style/nsStyleStruct.cpp
+++ b/layout/style/nsStyleStruct.cpp
@@ -2095,37 +2095,17 @@ private:
   // Since we always dispatch this runnable to the main thread, these will be
   // released on the main thread when the runnable itself is released.
   RefPtr<imgRequestProxy> mRequestProxy;
   RefPtr<css::ImageValue> mImageValue;
   RefPtr<ImageTracker> mImageTracker;
 };
 
 nsStyleImageRequest::nsStyleImageRequest(Mode aModeFlags,
-                                         imgRequestProxy* aRequestProxy,
-                                         css::ImageValue* aImageValue,
-                                         ImageTracker* aImageTracker)
-  : mRequestProxy(aRequestProxy)
-  , mImageValue(aImageValue)
-  , mImageTracker(aImageTracker)
-  , mModeFlags(aModeFlags)
-  , mResolved(true)
-{
-  MOZ_ASSERT(NS_IsMainThread());
-  MOZ_ASSERT(aImageValue);
-  MOZ_ASSERT(!!(aModeFlags & Mode::Track) == !!aImageTracker);
-
-  if (mRequestProxy) {
-    MaybeTrackAndLock();
-  }
-}
-
-nsStyleImageRequest::nsStyleImageRequest(
-    Mode aModeFlags,
-    mozilla::css::ImageValue* aImageValue)
+                                         css::ImageValue* aImageValue)
   : mImageValue(aImageValue)
   , mModeFlags(aModeFlags)
   , mResolved(false)
 {
 }
 
 nsStyleImageRequest::~nsStyleImageRequest()
 {

--- a/layout/style/nsStyleStruct.h
+++ b/layout/style/nsStyleStruct.h
@@ -211,40 +211,31 @@ private:
   nsStyleGradient(const nsStyleGradient& aOther) = delete;
   nsStyleGradient& operator=(const nsStyleGradient& aOther) = delete;
 };
 
 /**
  * A wrapper for an imgRequestProxy that supports off-main-thread creation
  * and equality comparison.
  *
- * An nsStyleImageRequest can be created in two ways:
- *
- * 1. Using the constructor that takes an imgRequestProxy.  This must
- *    be called from the main thread.  The nsStyleImageRequest is
- *    immediately considered "resolved", and the get() method that
- *    returns the imgRequestProxy can be called.
+ * An nsStyleImageRequest can be created using the constructor that takes the
+ * URL, base URI, referrer and principal that can be used to initiate an image
+ * load and produce an imgRequestProxy later.
  *
- * 2. Using the constructor that takes the URL, base URI, referrer
- *    and principal that can be used to inititiate an image load and
- *    produce an imgRequestProxy later.  This can be called from
- *    any thread.  The nsStyleImageRequest is not considered "resolved"
- *    at this point, and the Resolve() method must be called later
- *    to initiate the image load and make calls to get() valid.
+ * This can be called from any thread.  The nsStyleImageRequest is not
+ * considered "resolved" at this point, and the Resolve() method must be called
+ * later to initiate the image load and make calls to get() valid.
  *
  * Calls to TrackImage(), UntrackImage(), LockImage(), UnlockImage() and
  * RequestDiscard() are made to the imgRequestProxy and ImageTracker as
  * appropriate, according to the mode flags passed in to the constructor.
  *
- * The main thread constructor takes a pointer to the css::ImageValue that
- * is the specified url() value, while the off-main-thread constructor
- * creates a new css::ImageValue to represent the url() information passed
- * to the constructor.  This ImageValue is held on to for the comparisons done
- * in DefinitelyEquals(), so that we don't need to call into the non-OMT-safe
- * Equals() on the nsIURI objects returned from imgRequestProxy::GetURI().
+ * The constructor receives a css::ImageValue to represent the url()
+ * information, which is held on to for the comparisons done in
+ * DefinitelyEquals().
  */
 class nsStyleImageRequest
 {
 public:
   typedef mozilla::css::URLValueData URLValueData;
 
   // Flags describing whether the imgRequestProxy must be tracked in the
   // ImageTracker, whether LockImage/UnlockImage calls will be made
@@ -262,29 +253,19 @@ public:
 
     // The imgRequestProxy will have its RequestDiscard method called when
     // the nsStyleImageRequest is going away.
     //
     // This is currently used only for cursor images.
     Discard = 0x2,
   };
 
-  // Must be called from the main thread.
-  //
-  // aImageTracker must be non-null iff aModeFlags contains Track.
-  nsStyleImageRequest(Mode aModeFlags,
-                      imgRequestProxy* aRequestProxy,
-                      mozilla::css::ImageValue* aImageValue,
-                      mozilla::dom::ImageTracker* aImageTracker);
-
   // Can be called from any thread, but Resolve() must be called later
   // on the main thread before get() can be used.
-  nsStyleImageRequest(
-      Mode aModeFlags,
-      mozilla::css::ImageValue* aImageValue);
+  nsStyleImageRequest(Mode aModeFlags, mozilla::css::ImageValue* aImageValue);
 
   bool Resolve(nsPresContext*, const nsStyleImageRequest* aOldImageRequest);
   bool IsResolved() const { return mResolved; }
 
   imgRequestProxy* get() {
     MOZ_ASSERT(IsResolved(), "Resolve() must be called first");
     MOZ_ASSERT(NS_IsMainThread());
     return mRequestProxy.get();