diff --git a/image/SurfaceCache.cpp b/image/SurfaceCache.cpp
index 1555c79b09f7..92c68b38553e 100644
--- a/image/SurfaceCache.cpp
+++ b/image/SurfaceCache.cpp
@@ -655,22 +655,6 @@ public:
     return LookupResult(Move(ref), matchType);
   }
 
-  void RemoveEntry(const ImageKey    aImageKey,
-                   const SurfaceKey& aSurfaceKey)
-  {
-    RefPtr<ImageSurfaceCache> cache = GetImageCache(aImageKey);
-    if (!cache) {
-      return;  // No cached surfaces for this image.
-    }
-
-    RefPtr<CachedSurface> surface = cache->Lookup(aSurfaceKey);
-    if (!surface) {
-      return;  // Lookup in the per-image cache missed.
-    }
-
-    Remove(surface);
-  }
-
   bool CanHold(const Cost aCost) const
   {
     return aCost <= mMaxCost;
@@ -877,6 +861,22 @@ private:
     }
   }
 
+  void RemoveEntry(const ImageKey    aImageKey,
+                   const SurfaceKey& aSurfaceKey)
+  {
+    RefPtr<ImageSurfaceCache> cache = GetImageCache(aImageKey);
+    if (!cache) {
+      return;  // No cached surfaces for this image.
+    }
+
+    RefPtr<CachedSurface> surface = cache->Lookup(aSurfaceKey);
+    if (!surface) {
+      return;  // Lookup in the per-image cache missed.
+    }
+
+    Remove(surface);
+  }
+
   struct SurfaceTracker : public nsExpirationTracker<CachedSurface, 2>
   {
     explicit SurfaceTracker(uint32_t aSurfaceCacheExpirationTimeMS)
@@ -1095,16 +1095,6 @@ SurfaceCache::UnlockEntries(const ImageKey aImageKey)
   }
 }
 
-/* static */ void
-SurfaceCache::RemoveEntry(const ImageKey    aImageKey,
-                          const SurfaceKey& aSurfaceKey)
-{
-  if (sInstance) {
-    MutexAutoLock lock(sInstance->GetMutex());
-    sInstance->RemoveEntry(aImageKey, aSurfaceKey);
-  }
-}
-
 /* static */ void
 SurfaceCache::RemoveImage(Image* aImageKey)
 {
diff --git a/image/SurfaceCache.h b/image/SurfaceCache.h
index afd48f3ad5e3..7c4b2395a0e9 100644
--- a/image/SurfaceCache.h
+++ b/image/SurfaceCache.h
@@ -269,9 +269,8 @@ struct SurfaceCache
    * directly. (They couldn't, since placeholders don't have an associated
    * surface.)
    *
-   * Once inserted, placeholders can be removed using RemoveEntry() or
-   * RemoveImage(), just like a real cache entry.  They're automatically removed
-   * when a real entry that matches the placeholder is inserted with Insert().
+   * Placeholders are automatically removed when a real entry that matches the
+   * placeholder is inserted with Insert(), or when RemoveImage() is called.
    *
    * @param aImageKey       Key data identifying which image the cache entry
    *                        belongs to.
@@ -317,9 +316,8 @@ struct SurfaceCache
    * until the next UnlockImage() or UnlockSurfaces() call for that image. Any
    * other cache entries owned by the image may expire at any time.
    *
-   * Regardless of locking, any of an image's cache entries may be removed using
-   * RemoveEntry(), and all of an image's cache entries are removed by
-   * RemoveImage(), whether the image is locked or not.
+   * All of an image's cache entries are removed by RemoveImage(), whether the
+   * image is locked or not.
    *
    * It's safe to call LockImage() on an image that's already locked; this has
    * no effect.
@@ -365,22 +363,6 @@ struct SurfaceCache
    */
   static void UnlockEntries(const ImageKey aImageKey);
 
-  /**
-   * Removes a cache entry (either a real or placeholder) from the cache, if
-   * it's present. If it's not present, RemoveEntry() has no effect.
-   *
-   * Use this function to remove individual cache entries that have become
-   * invalid.  Prefer RemoveImage() or DiscardAll() when they're applicable, as
-   * they have much better performance than calling this function repeatedly.
-   *
-   * @param aImageKey       Key data identifying which image the cache entry
-   *                        belongs to.
-   * @param aSurfaceKey     Key data which uniquely identifies the requested
-   *                        cache entry.
-   */
-  static void RemoveEntry(const ImageKey    aImageKey,
-                          const SurfaceKey& aSurfaceKey);
-
   /**
    * Removes all cache entries (both real and placeholder) associated with the
    * given image from the cache.  If the image is locked, it is automatically
@@ -398,8 +380,7 @@ struct SurfaceCache
    * Evicts all evictable entries from the cache.
    *
    * All entries are evictable except for entries associated with locked images.
-   * Non-evictable entries can only be removed by RemoveEntry() or
-   * RemoveImage().
+   * Non-evictable entries can only be removed by RemoveImage().
    */
   static void DiscardAll();