predictors: Add the request priority to the reource_prefetch_predictor DB.

chrome/browser/predictors/resource_prefetch_predictor_tables.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 CHROME_BROWSER_PREDICTORS_RESOURCE_PREFETCH_PREDICTOR_TABLES_H_
 #define CHROME_BROWSER_PREDICTORS_RESOURCE_PREFETCH_PREDICTOR_TABLES_H_
 
 #include <stddef.h>
 
 #include <map>
 #include <string>
 #include <vector>
 
 #include "base/macros.h"
 #include "base/time/time.h"
 #include "chrome/browser/predictors/predictor_table_base.h"
 #include "chrome/browser/predictors/resource_prefetch_common.h"
 #include "content/public/common/resource_type.h"
+#include "net/base/request_priority.h"
 #include "url/gurl.h"
 
 namespace sql {
 class Statement;
 }
 
 namespace predictors {
 
 // Interface for database tables used by the ResourcePrefetchPredictor.
 // All methods except the constructor and destructor need to be called on the DB
@@ skipping 10 matching lines @@
   // required for the page or host.
   struct ResourceRow {
     ResourceRow();
     ResourceRow(const ResourceRow& other);
     ResourceRow(const std::string& main_frame_url,
                 const std::string& resource_url,
                 content::ResourceType resource_type,
                 int number_of_hits,
                 int number_of_misses,
                 int consecutive_misses,
-                double average_position);
+                double average_position,
+                net::RequestPriority priority);
     void UpdateScore();
     bool operator==(const ResourceRow& rhs) const;
 
     // Stores the host for host based data, main frame Url for the Url based
     // data. This field is cleared for efficiency reasons and the code outside
     // this class should not assume it is set.
     std::string primary_key;
 
     GURL resource_url;
     content::ResourceType resource_type;
     size_t number_of_hits;
     size_t number_of_misses;
     size_t consecutive_misses;
     double average_position;
+    net::RequestPriority priority;
 
     // Not stored.
     float score;
   };
   typedef std::vector<ResourceRow> ResourceRows;
 
   // Sorts the ResourceRows by score, descending.
   struct ResourceRowSorter {
     bool operator()(const ResourceRow& x, const ResourceRow& y) const;
   };
@@ skipping 61 matching lines @@
                         const std::vector<std::string>& keys);
 
   // Returns true if the strings in the |data| are less than |kMaxStringLength|
   // in length.
   bool StringsAreSmallerThanDBLimit(const PrefetchData& data) const;
 
   // PredictorTableBase methods.
   void CreateTableIfNonExistent() override;
   void LogDatabaseStats() override;
 
+  bool DropTablesIfOutdated(sql::Connection* db);
+
   // Helpers to return Statements for cached Statements. The caller must take
   // ownership of the return Statements.
   sql::Statement* GetUrlResourceDeleteStatement();
   sql::Statement* GetUrlResourceUpdateStatement();
   sql::Statement* GetUrlMetadataDeleteStatement();
   sql::Statement* GetUrlMetadataUpdateStatement();
 
   sql::Statement* GetHostResourceDeleteStatement();
   sql::Statement* GetHostResourceUpdateStatement();
   sql::Statement* GetHostMetadataDeleteStatement();
   sql::Statement* GetHostMetadataUpdateStatement();
 
   DISALLOW_COPY_AND_ASSIGN(ResourcePrefetchPredictorTables);
 };
 
 }  // namespace predictors
 
 #endif  // CHROME_BROWSER_PREDICTORS_RESOURCE_PREFETCH_PREDICTOR_TABLES_H_