Prepare HistoryProvider for componentization

components/omnibox/autocomplete_provider_client.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_CLIENT_H_
 #define COMPONENTS_OMNIBOX_AUTOCOMPLETE_PROVIDER_CLIENT_H_
 
 #include "base/strings/string16.h"
 #include "components/history/core/browser/keyword_id.h"
 #include "components/metrics/proto/omnibox_event.pb.h"
 
 struct AutocompleteMatch;
 class AutocompleteSchemeClassifier;
 class GURL;
 
+namespace bookmarks {
+class BookmarkModel;
+}
+
 namespace history {
+class HistoryService;
 class URLDatabase;
 }
 
 namespace net {
 class URLRequestContextGetter;
 }
 
 class AutocompleteProviderClient {
  public:
   virtual ~AutocompleteProviderClient() {}
@@ skipping 10 matching lines @@
 
   // Returns true when suggest support is enabled.
   virtual bool SearchSuggestEnabled() = 0;
 
   // Returns whether the bookmark bar is visible on all tabs.
   virtual bool ShowBookmarkBar() = 0;
 
   // Returns the scheme classifier.
   virtual const AutocompleteSchemeClassifier& SchemeClassifier() = 0;
 
+  // Returns the HistoryService.

[Peter Kasting, 2015/06/12 16:20:23]

The order of these functions seems totally random.  For example, this seems like
it is very similar to InMemoryDatabase(), and not at all similar to Classify(),
but the latter is closer than the former.

Maybe these should be grouped: getters for various services/objects, oracle
functions, other utilities.  Or some other form of grouping that makes sense? 
Anything that isn't so random-seeming.

[blundell, 2015/06/15 08:51:33]

Agreed. I'll send you a separate CL for this as the reordering would introduce a
bunch of churn in this CL.

+  virtual history::HistoryService* HistoryService() = 0;
+
+  // Returns the bookmarks:BookmarkModel
+  virtual bookmarks::BookmarkModel* BookmarkModel() = 0;
+
   // Given some string |text| that the user wants to use for navigation,
   // determines how it should be interpreted.
   virtual void Classify(
       const base::string16& text,
       bool prefer_keyword,
       bool allow_exact_keyword_match,
       metrics::OmniboxEventProto::PageClassification page_classification,
       AutocompleteMatch* match,
       GURL* alternate_nav_url) = 0;
 
   // Returns the in-memory URL database.
   virtual history::URLDatabase* InMemoryDatabase() = 0;
 
   // Deletes all URL and search term entries matching the given |term| and
   // |keyword_id| from history.
   virtual void DeleteMatchingURLsForKeywordFromHistory(
       history::KeywordID keyword_id,
       const base::string16& term) = 0;
 
   // Returns whether the user has tab sync enabled and tab sync is unencrypted.
   virtual bool TabSyncEnabledAndUnencrypted() = 0;
 
   // Starts prefetching the image at the given |url|.
   virtual void PrefetchImage(const GURL& url) = 0;
 };
 
 #endif  // COMPONENTS_OMNIBOX_AUTOCOMPLETE_PROVIDER_CLIENT_H_