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

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

Index: chrome/browser/ui/cocoa/location_bar/location_bar_view_mac.h
diff --git a/chrome/browser/ui/cocoa/location_bar/location_bar_view_mac.h b/chrome/browser/ui/cocoa/location_bar/location_bar_view_mac.h
index 1300cc9bd0fefa087e483c08fd2c6d95ccf418bc..a9fc492eaab625625f2a6226940d12eb70444b7f 100644
--- a/chrome/browser/ui/cocoa/location_bar/location_bar_view_mac.h
+++ b/chrome/browser/ui/cocoa/location_bar/location_bar_view_mac.h
@@ -22,6 +22,7 @@
 #include "components/prefs/pref_member.h"
 #include "components/security_state/security_state_model.h"
 #include "components/zoom/zoom_event_manager_observer.h"
+#include "components/omnibox/common/omnibox_focus_state.h"
 
 @class AutocompleteTextField;
 class CommandUpdater;
@@ -182,6 +183,7 @@ class LocationBarViewMac : public LocationBar,
   ToolbarModel* GetToolbarModel() override;
   const ToolbarModel* GetToolbarModel() const override;
   content::WebContents* GetWebContents() override;
+  void OnFocusChanged(OmniboxFocusState state) override;
 
   bool ShouldShowEVBubble() const;
 
@@ -267,6 +269,9 @@ class LocationBarViewMac : public LocationBar,
   // position the decoration will be drawn at.
   void UpdateAccessibilityViewPosition(LocationBarDecoration* decoration);
 
+  // Returns true when omnibox has focus.
+  bool HasFocus() const;
+
   std::unique_ptr<OmniboxViewMac> omnibox_view_;
 
   AutocompleteTextField* field_;  // owned by tab controller
@@ -312,6 +317,9 @@ class LocationBarViewMac : public LocationBar,
   // Used to change the visibility of the star decoration.
   BooleanPrefMember edit_bookmarks_enabled_;
 
+  // Used to confirm the visibility of the keyword hint decoration.
+  OmniboxFocusState focus_state_;
+
   // Indicates whether or not the location bar is currently visible.
   bool location_bar_visible_;
 
@@ -332,7 +340,6 @@ class LocationBarViewMac : public LocationBar,
 
   // Used to schedule a task for the first run info bubble.
   base::WeakPtrFactory<LocationBarViewMac> weak_ptr_factory_;
-
   DISALLOW_COPY_AND_ASSIGN(LocationBarViewMac);
 };