Bug 946781 - part 5 - measure the proto and iface cache from within xpconnect; r=bholley,njn

js/xpconnect/src/XPCJSRuntime.cpp

@@ -2728,6 +2728,10 @@ JSReporter::CollectReports(WindowPaths *windowPaths,
                  KIND_HEAP, sizeInfo.mScopeAndMapSize,
                  "Memory used by XPConnect scopes.");
 
+    REPORT_BYTES(NS_LITERAL_CSTRING("explicit/xpconnect/proto-iface-cache"),
+                 KIND_HEAP, sizeInfo.mProtoAndIfaceCacheSize,
+                 "Memory used for prototype and interface binding caches.");
+
     REPORT_BYTES(NS_LITERAL_CSTRING("explicit/xpconnect/js-component-loader"),
                  KIND_HEAP, jsComponentLoaderSize,
                  "Memory used by XPConnect's JS component loader.");

js/xpconnect/src/XPCWrappedNativeScope.cpp

@@ -679,6 +679,12 @@ XPCWrappedNativeScope::AddSizeOfIncludingThis(ScopeSizeInfo* scopeSizeInfo)
     scopeSizeInfo->mScopeAndMapSize +=
         mWrappedNativeProtoMap->SizeOfIncludingThis(scopeSizeInfo->mMallocSizeOf);
 
+    if (dom::HasProtoAndIfaceArray(mGlobalJSObject)) {
+        dom::ProtoAndIfaceArray* cache = dom::GetProtoAndIfaceArray(mGlobalJSObject);
+        scopeSizeInfo->mProtoAndIfaceCacheSize +=
+            cache->SizeOfIncludingThis(scopeSizeInfo->mMallocSizeOf);
+    }
+
     // There are other XPCWrappedNativeScope members that could be measured;
     // the above ones have been seen by DMD to be worth measuring.  More stuff
     // may be added later.

js/xpconnect/src/xpcprivate.h

@@ -1139,10 +1139,14 @@ public:
 
     struct ScopeSizeInfo {
         ScopeSizeInfo(mozilla::MallocSizeOf mallocSizeOf)
-            : mMallocSizeOf(mallocSizeOf), mScopeAndMapSize(0) {}
+            : mMallocSizeOf(mallocSizeOf),
+              mScopeAndMapSize(0),
+              mProtoAndIfaceCacheSize(0)
+        {}
 
         mozilla::MallocSizeOf mMallocSizeOf;
         size_t mScopeAndMapSize;
+        size_t mProtoAndIfaceCacheSize;
     };
 
     static void