[WIP] Add SharedMemoryTracker to dump base::SharedMemory usage

services/ui/public/cpp/bitmap/child_shared_bitmap_manager.cc

Index: services/ui/public/cpp/bitmap/child_shared_bitmap_manager.cc
diff --git a/services/ui/public/cpp/bitmap/child_shared_bitmap_manager.cc b/services/ui/public/cpp/bitmap/child_shared_bitmap_manager.cc
index 92fc4300b1891aba9d4cc158ca79d771fb9723b3..08fbcdcc00108b7549502012034352487d12ffd3 100644
--- a/services/ui/public/cpp/bitmap/child_shared_bitmap_manager.cc
+++ b/services/ui/public/cpp/bitmap/child_shared_bitmap_manager.cc
@@ -31,6 +31,8 @@ class ChildSharedBitmap : public cc::SharedBitmap {
       : cc::SharedBitmap(static_cast<uint8_t*>(shared_memory->memory()), id),
         shared_bitmap_manager_ptr_(shared_bitmap_manager_ptr) {}
 
+  // TODO(hajimehoshi): shared bitmpa is not reffered in this case?
+
   ChildSharedBitmap(
       const scoped_refptr<cc::mojom::ThreadSafeSharedBitmapManagerAssociatedPtr>
           shared_bitmap_manager_ptr,
@@ -46,6 +48,10 @@ class ChildSharedBitmap : public cc::SharedBitmap {
     (*shared_bitmap_manager_ptr_)->DidDeleteSharedBitmap(id());
   }
 
+  base::SharedMemory* GetSharedMemory() const override {
+    return shared_memory_holder_.get();
+  }
+
  private:
   scoped_refptr<cc::mojom::ThreadSafeSharedBitmapManagerAssociatedPtr>
       shared_bitmap_manager_ptr_;