Bug 1615539 - Fix explicit image memory reporting broken on Windows. r=jrmuizel

Differential Revision: https://phabricator.services.mozilla.com/D62899

--HG--
extra : moz-landing-system : lando

image/imgLoader.cpp

@@ -492,7 +492,9 @@ class imgMemoryReporter final : public nsIMemoryReporter {
                 "Decoded image data which isn't stored on the heap.",
                 aCounter.DecodedNonHeap());
 
-    ReportValue(aHandleReport, aData, KIND_OTHER, aPathPrefix,
+    // We don't know for certain whether or not it is on the heap, so let's
+    // just report it as non-heap for reporting purposes.
+    ReportValue(aHandleReport, aData, KIND_NONHEAP, aPathPrefix,
                 "decoded-unknown",
                 "Decoded image data which is unknown to be on the heap or not.",
                 aCounter.DecodedUnknown());