Send important client side event information to the server.

chrome/browser/sync/engine/download_updates_command_unittest.cc

Index: chrome/browser/sync/engine/download_updates_command_unittest.cc
diff --git a/chrome/browser/sync/engine/download_updates_command_unittest.cc b/chrome/browser/sync/engine/download_updates_command_unittest.cc
index 1e2aa2f63ce2e267ed669192433523bbd3eb0e95..1b647a03a21d7e3329641ef30274f58ce96ca705 100644
--- a/chrome/browser/sync/engine/download_updates_command_unittest.cc
+++ b/chrome/browser/sync/engine/download_updates_command_unittest.cc
@@ -11,6 +11,7 @@
 #include "chrome/browser/sync/test/engine/proto_extension_validator.h"
 #include "chrome/browser/sync/test/engine/syncer_command_test.h"
 
+using ::testing::_;
 namespace browser_sync {
 
 using syncable::FIRST_REAL_MODEL_TYPE;
@@ -132,4 +133,15 @@ TEST_F(DownloadUpdatesCommandTest, ExecuteWithPayloads) {
   command_.ExecuteImpl(session(source));
 }
 
+TEST_F(DownloadUpdatesCommandTest, VerifyAppendDebugInfo) {
+  sync_pb::ClientToServerMessage client_to_server_message;
+  EXPECT_CALL(*(mock_debug_info_getter()), GetAndClearDebugInfo(_))
+      .Times(1);
+  command_.AppendClientDebugInfoIfNeeded(session(), &client_to_server_message);
+
+  // Now try to add it once more and make sure |GetAndClearDebugInfo| is not
+  // called.
+  command_.AppendClientDebugInfoIfNeeded(session(), &client_to_server_message);
+}
+
 }  // namespace browser_sync