Add MDP for TabRestorer.

components/sessions/core/serialized_navigation_entry.cc

Index: components/sessions/core/serialized_navigation_entry.cc
diff --git a/components/sessions/core/serialized_navigation_entry.cc b/components/sessions/core/serialized_navigation_entry.cc
index 08685eb36021a03d8ca5a10c96d00e145d5c45fb..79c54cf56280be627ac2b2e5749cdfe61290f0ee 100644
--- a/components/sessions/core/serialized_navigation_entry.cc
+++ b/components/sessions/core/serialized_navigation_entry.cc
@@ -8,10 +8,18 @@
 
 #include "base/pickle.h"
 #include "base/strings/utf_string_conversions.h"
+#include "base/trace_event/estimate_memory_usage.h"
 #include "components/sessions/core/serialized_navigation_driver.h"
 #include "components/sync/base/time.h"
 #include "components/sync/protocol/session_specifics.pb.h"
 
+// TODO(dskiba): move somemhere
+size_t EstimateMemoryUsage(const GURL& url) {
+  using base::trace_event::EstimateMemoryUsage;
+  return EstimateMemoryUsage(url.possibly_invalid_spec()) +
+         (url.inner_url() ? EstimateMemoryUsage(*url.inner_url()) : 0);
+}
+
 namespace sessions {
 
 // TODO(treib): Remove, not needed anymore. crbug.com/627747
@@ -500,4 +508,19 @@ sync_pb::TabNavigation SerializedNavigationEntry::ToSyncData() const {
   return sync_data;
 }
 
+size_t SerializedNavigationEntry::EstimateMemoryUsage() const {
+  using base::trace_event::EstimateMemoryUsage;
+  return
+      EstimateMemoryUsage(referrer_url_) +
+      EstimateMemoryUsage(virtual_url_) +
+      EstimateMemoryUsage(title_) +
+      EstimateMemoryUsage(encoded_page_state_) +
+      EstimateMemoryUsage(original_request_url_) +
+      EstimateMemoryUsage(search_terms_) +
+      EstimateMemoryUsage(favicon_url_) +
+      EstimateMemoryUsage(redirect_chain_) +
+      EstimateMemoryUsage(content_pack_categories_) +
+      EstimateMemoryUsage(extended_info_map_);
+}
+
 }  // namespace sessions