[WinCairo] Add memory usage of LibcMalloc category

https://bugs.webkit.org/show_bug.cgi?id=239660

Reviewed by Ross Kirsling.

WinCairo's memory timeline just displays JavaScript memory usage. Adding
this info shows also Page
memory usage.

* page/win/ResourceUsageThreadWin.cpp:
(WebCore::ResourceUsageThread::platformCollectMemoryData):

Canonical link: https://commits.webkit.org/250674@main
git-svn-id: https://svn.webkit.org/repository/webkit/trunk@294377 268f45cc-cd09-0410-ab3c-d52691b4dbfc

Source/WebCore/page/win/ResourceUsageThreadWin.cpp

@@ -118,7 +118,7 @@ void ResourceUsageThread::platformCollectCPUData(JSC::VM*, ResourceUsageData& da
 
 void ResourceUsageThread::platformCollectMemoryData(JSC::VM* vm, ResourceUsageData& data)
 {
-    data.totalDirtySize = memoryUsage();
+    auto usage = data.totalDirtySize = memoryUsage();
 
     size_t currentGCHeapCapacity = vm->heap.blockBytesAllocated();
     size_t currentGCOwnedExtra = vm->heap.extraMemorySize();
@@ -129,6 +129,14 @@ void ResourceUsageThread::platformCollectMemoryData(JSC::VM* vm, ResourceUsageDa
     data.categories[MemoryCategory::GCOwned].dirtySize = currentGCOwnedExtra - currentGCOwnedExternal;
     data.categories[MemoryCategory::GCOwned].externalSize = currentGCOwnedExternal;
 
+    usage -= currentGCHeapCapacity;
+    // Following ResourceUsageThreadCocoa implementation
+    auto currentGCOwnedGenerallyInMalloc = currentGCOwnedExtra - currentGCOwnedExternal;
+    if (currentGCOwnedGenerallyInMalloc < usage)
+        usage -= currentGCOwnedGenerallyInMalloc;
+
+    data.categories[MemoryCategory::LibcMalloc].dirtySize = usage;
+
     data.totalExternalSize = currentGCOwnedExternal;
 
     data.timeOfNextEdenCollection = data.timestamp + vm->heap.edenActivityCallback()->timeUntilFire().value_or(Seconds(std::numeric_limits<double>::infinity()));