[tracing] Show the local storage databases under dom_storage

content/browser/dom_storage/dom_storage_database.h

Index: content/browser/dom_storage/dom_storage_database.h
diff --git a/content/browser/dom_storage/dom_storage_database.h b/content/browser/dom_storage/dom_storage_database.h
index 75416374edee676e1a5ce2f7e27a52edd709df1f..9f5fd4a61be6e8426e0857e0f7c1b5a3d5324810 100644
--- a/content/browser/dom_storage/dom_storage_database.h
+++ b/content/browser/dom_storage/dom_storage_database.h
@@ -7,6 +7,7 @@
 
 #include <map>
 #include <memory>
+#include <string>
 
 #include "base/files/file_path.h"
 #include "base/gtest_prod_util.h"
@@ -16,6 +17,12 @@
 #include "content/common/dom_storage/dom_storage_types.h"
 #include "sql/connection.h"
 
+namespace base {
+namespace trace_event {
+class ProcessMemoryDump;
+}
+}
+
 namespace content {
 
 // Represents a SQLite based backing for DOM storage data. This
@@ -40,6 +47,10 @@ class CONTENT_EXPORT DOMStorageDatabase {
   // will be removed and all others will be inserted/updated as appropriate.
   bool CommitChanges(bool clear_all_first, const DOMStorageValuesMap& changes);
 
+  // Adds memory statistics of the database to |pmd| for tracing.
+  void ReportMemoryUsage(base::trace_event::ProcessMemoryDump* pmd,
+                         const std::string& name);
+
   // Simple getter for the path we were constructed with.
   const base::FilePath& file_path() const { return file_path_; }