removing ShouldHideTopMatch

components/metrics/proto/omnibox_event.proto

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // Stores information about an omnibox interaction.
 
 syntax = "proto2";
 
 option optimize_for = LITE_RUNTIME;
 option java_outer_classname = "OmniboxEventProtos";
@@ skipping 21 matching lines @@
   // suggestion.  This is usually the result of pressing backspace or delete.
   optional bool just_deleted_text = 11;
 
   // The number of terms that the user typed in the omnibox.
   optional int32 num_typed_terms = 4;
 
   // The index of the item that the user selected in the omnibox popup list.
   // This corresponds the index of the |suggestion| below.
   optional int32 selected_index = 5;
 
-  // Whether or not the top match was hidden in the omnibox suggestions
-  // dropdown.
-  optional bool is_top_result_hidden_in_dropdown = 14;
+  // DEPRECATED. Whether or not the top match was hidden in the omnibox
+  // suggestions dropdown.
+  optional bool is_top_result_hidden_in_dropdown = 14 [deprecated = true];

[Mark P, 2015/06/10 04:26:18]

Given that changed the name of the field internally, you should change the name
of the field here too.  We want the internal and external files to remain in
sync.

[dschuyler, 2015/06/10 18:29:33]

Done.

 
   // Whether the omnibox popup is open.  It can be closed if, for instance,
   // the user clicks in the omnibox and hits return to reload the same page.
   // If the popup is closed, the suggestion list will contain only one item
   // and selected_index will be 0 (pointing to that single item).  Because
   // paste-and-search/paste-and-go actions ignore the current content of the
   // omnibox dropdown (if it is open) when they happen, we pretend the
   // dropdown is closed when logging these.
   optional bool is_popup_open = 15;
 
@@ skipping 219 matching lines @@
     // The number of times this provider returned a non-zero number of
     // suggestions during this omnibox session.
     // Note that each provider may define a session differently for its
     // purposes.
     optional int32 times_returned_results_in_session = 5;
   }
   // A list of diagnostic information about each provider.  Providers
   // will appear at most once in this list.
   repeated ProviderInfo provider_info = 12;
 }