Add support for providers called when the omnibox is focused.

components/omnibox/autocomplete_provider.h

 // 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.
 
 #ifndef COMPONENTS_OMNIBOX_AUTOCOMPLETE_PROVIDER_H_
 #define COMPONENTS_OMNIBOX_AUTOCOMPLETE_PROVIDER_H_
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "base/strings/string16.h"
@@ skipping 179 matching lines @@
 
   // Returns the set of matches for the current query.
   const ACMatches& matches() const { return matches_; }
 
   // Returns whether the provider is done processing the query.
   bool done() const { return done_; }
 
   // Returns this provider's type.
   Type type() const { return type_; }
 
+  // Returns whether the provider wants to provide matches in response to the
+  // omnibox being focused.
+  virtual bool ProvidesMatchesOnOmniboxFocus() const;
+
   // Returns a string describing this provider's type.
   const char* GetName() const;
 
   // A suggested upper bound for how many matches a provider should return.
   // TODO(pkasting): http://b/1111299 , http://b/933133 This should go away once
   // we have good relevance heuristics; the controller should handle all
   // culling.
   static const size_t kMaxMatches;
 
  protected:
@@ skipping 29 matching lines @@
   ACMatches matches_;
   bool done_;
 
   Type type_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(AutocompleteProvider);
 };
 
 #endif  // COMPONENTS_OMNIBOX_AUTOCOMPLETE_PROVIDER_H_