Fixed the issue shows keyword hint when omnibox loses its focus.

chrome/browser/ui/cocoa/location_bar/location_bar_view_mac.mm

 // Copyright 2012 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.
 
 #import "chrome/browser/ui/cocoa/location_bar/location_bar_view_mac.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #import "base/mac/mac_util.h"
 #include "base/stl_util.h"
@@ skipping 477 matching lines @@
     location_icon_decoration_->SetVisible(false);
     selected_keyword_decoration_->SetVisible(true);
     selected_keyword_decoration_->SetKeyword(short_name, is_extension_keyword);
     // Note: the first time through this code path the
     // |selected_keyword_decoration_| has no image set because under Material
     // Design we need to set its color, which we cannot do until we know the
     // theme (by being installed in a browser window).
     selected_keyword_decoration_->SetImage(GetKeywordImage(keyword));
   } else if (!keyword.empty() && is_keyword_hint) {
     keyword_hint_decoration_->SetKeyword(short_name, is_extension_keyword);
-    keyword_hint_decoration_->SetVisible(true);
+    if (focus_state_ == OMNIBOX_FOCUS_VISIBLE) {
+      keyword_hint_decoration_->SetVisible(true);
+    }
   } else if (ShouldShowEVBubble()) {
     // Switch from location icon to show the EV bubble instead.
     location_icon_decoration_->SetVisible(false);
     security_state_bubble_decoration_->SetVisible(true);
 
     base::string16 label(GetToolbarModel()->GetEVCertName());
     security_state_bubble_decoration_->SetFullLabel(
         base::SysUTF16ToNSString(label));
 
     // This is true for EV certificate since the certificate should be
@@ skipping 168 matching lines @@
 }
 
 const ToolbarModel* LocationBarViewMac::GetToolbarModel() const {
   return browser_->toolbar_model();
 }
 
 WebContents* LocationBarViewMac::GetWebContents() {
   return browser_->tab_strip_model()->GetActiveWebContents();
 }
 
+void LocationBarViewMac::OnFocusChanged(OmniboxFocusState state) {
+  focus_state_ = state;
+
+  Layout();
+}
+
 bool LocationBarViewMac::ShouldShowEVBubble() const {
   return (GetToolbarModel()->GetSecurityLevel(false) ==
           security_state::SecurityStateModel::EV_SECURE) &&
          should_show_secure_verbose_;
 }
 
 bool LocationBarViewMac::ShouldShowSecurityState() const {
   security_state::SecurityStateModel::SecurityLevel security =
       GetToolbarModel()->GetSecurityLevel(false);
   bool has_verbose_for_security =
@@ skipping 250 matching lines @@
     OnDecorationsChanged();
 }
 
 std::vector<NSView*> LocationBarViewMac::GetDecorationAccessibilityViews() {
   std::vector<LocationBarDecoration*> decorations = GetDecorations();
   std::vector<NSView*> views;
   for (auto* decoration : decorations)
     views.push_back(decoration->GetAccessibilityView());
   return views;
 }