[tracing] Remove MemoryAllocatorDump::process_memory_dump

base/trace_event/memory_allocator_dump.h

Index: base/trace_event/memory_allocator_dump.h
diff --git a/base/trace_event/memory_allocator_dump.h b/base/trace_event/memory_allocator_dump.h
index 2e6b08ab32ffd939b62eb5c1a51aa9aaedbb632d..c781f071bba40ab08c25dcb18ec1f59fc1b1fc12 100644
--- a/base/trace_event/memory_allocator_dump.h
+++ b/base/trace_event/memory_allocator_dump.h
@@ -69,11 +69,6 @@ class BASE_EXPORT MemoryAllocatorDump {
   // Called at trace generation time to populate the TracedValue.
   void AsValueInto(TracedValue* value) const;
 
-  // Get the ProcessMemoryDump instance that owns this.
-  ProcessMemoryDump* process_memory_dump() const {
-    return process_memory_dump_;
-  }
-
   // Use enum Flags to set values.
   void set_flags(int flags) { flags_ |= flags; }
   void clear_flags(int flags) { flags_ &= ~flags; }