predictors: Refactor resource_prefetch_predictor_tables.

chrome/browser/predictors/resource_prefetch_predictor_tables.h

Index: chrome/browser/predictors/resource_prefetch_predictor_tables.h
diff --git a/chrome/browser/predictors/resource_prefetch_predictor_tables.h b/chrome/browser/predictors/resource_prefetch_predictor_tables.h
index 6588b546c69e8eae8536ff60e4c4b840c5e3b7f8..c3b2eeda4de4c4a9349c15cd4bb6f89e585efa89 100644
--- a/chrome/browser/predictors/resource_prefetch_predictor_tables.h
+++ b/chrome/browser/predictors/resource_prefetch_predictor_tables.h
@@ -8,13 +8,13 @@
 #include <stddef.h>
 
 #include <map>
+#include <memory>
 #include <string>
 #include <vector>
 
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
-#include "base/time/time.h"
 #include "chrome/browser/predictors/predictor_table_base.h"
 #include "chrome/browser/predictors/resource_prefetch_common.h"
 #include "chrome/browser/predictors/resource_prefetch_predictor.pb.h"
@@ -29,6 +29,7 @@ class Statement;
 namespace predictors {
 
 // From resource_prefetch_predictor.proto.
+using ResourceData = PrefetchData_ResourceData;
 using RedirectStat = RedirectData_RedirectStat;
 
 // Interface for database tables used by the ResourcePrefetchPredictor.
@@ -37,30 +38,11 @@ using RedirectStat = RedirectData_RedirectStat;
 //
 // Currently manages:
 //  - UrlResourceTable - resources per Urls.
-//  - UrlMetadataTable - misc data for Urls (like last visit time).
 //  - UrlRedirectTable - redirects per Urls.
 //  - HostResourceTable - resources per host.
-//  - HostMetadataTable - misc data for hosts.
 //  - HostRedirectTable - redirects per host.
 class ResourcePrefetchPredictorTables : public PredictorTableBase {
  public:
-  // Aggregated data for a Url or Host. Although the data differs slightly, we
-  // store them in the same structure, because most of the fields are common and
-  // it allows us to use the same functions.
-  struct PrefetchData {
-    PrefetchData(PrefetchKeyType key_type, const std::string& primary_key);
-    PrefetchData(const PrefetchData& other);
-    ~PrefetchData();
-
-    bool is_host() const { return key_type == PREFETCH_KEY_TYPE_HOST; }
-
-    // Is the data a host as opposed to a Url?
-    PrefetchKeyType key_type;  // Not const to be able to assign.
-    std::string primary_key;   // is_host() ? host : main frame url.
-
-    base::Time last_visit;
-    std::vector<ResourceData> resources;
-  };
   // Map from primary key to PrefetchData for the key.
   typedef std::map<std::string, PrefetchData> PrefetchDataMap;
 
@@ -114,7 +96,7 @@ class ResourcePrefetchPredictorTables : public PredictorTableBase {
 
  private:
   // Represents the type of information that is stored in prefetch database.
-  enum class PrefetchDataType { RESOURCE, REDIRECT, METADATA };
+  enum class PrefetchDataType { RESOURCE, REDIRECT };
 
   enum class TableOperationType { INSERT, REMOVE };
 
@@ -133,8 +115,7 @@ class ResourcePrefetchPredictorTables : public PredictorTableBase {
   // Helper functions below help perform functions on the Url and host table
   // using the same code.
   void GetAllResourceDataHelper(PrefetchKeyType key_type,
-                                PrefetchDataMap* data_map,
-                                std::vector<std::string>* to_delete);
+                                PrefetchDataMap* data_map);
   void GetAllRedirectDataHelper(PrefetchKeyType key_type,
                                 RedirectDataMap* redirect_map);
   bool UpdateResourceDataHelper(PrefetchKeyType key_type,