[tracing] Adding class-wise memory statistics to blink gc memory dumps

Source/platform/heap/Heap.cpp

Index: Source/platform/heap/Heap.cpp
diff --git a/Source/platform/heap/Heap.cpp b/Source/platform/heap/Heap.cpp
index d5fd5556f80b6e9c9b0e82755844ac35d282a18c..a56d46ec7a348bdee8b5b42357060fdbf82d651a 100644
--- a/Source/platform/heap/Heap.cpp
+++ b/Source/platform/heap/Heap.cpp
@@ -1512,9 +1512,17 @@ void NormalPage::takeSnapshot(String dumpName, size_t pageIndex, ThreadState::GC
         } else if (header->isMarked()) {
             liveCount++;
             liveSize += header->size();
+
+            size_t tag = info.getClassTag(header->gcInfoIndex());
+            info.liveCount[tag]++;
+            info.liveSize[tag] += header->size();
         } else {
             deadCount++;
             deadSize += header->size();
+
+            size_t tag = info.getClassTag(header->gcInfoIndex());
+            info.deadCount[tag]++;
+            info.deadSize[tag] += header->size();
         }
     }
 
@@ -1714,12 +1722,17 @@ void LargeObjectPage::takeSnapshot(String dumpName, size_t pageIndex, ThreadStat
     size_t liveCount = 0;
     size_t deadCount = 0;
     HeapObjectHeader* header = heapObjectHeader();
+    size_t tag = info.getClassTag(header->gcInfoIndex());
     if (header->isMarked()) {
         liveCount = 1;
-        liveSize += header->size();
+        liveSize += header->payloadSize();
+        info.liveCount[tag]++;
+        info.liveSize[tag] += header->size();
     } else {
         deadCount = 1;
-        deadSize += header->size();
+        deadSize += header->payloadSize();
+        info.deadCount[tag]++;
+        info.deadSize[tag] += header->size();
     }
 
     pageDump->AddScalar("live_count", "objects", liveCount);