Revert of Revert CL 117933003. Re-add resource speculative prefetching code.

chrome/browser/predictors/predictor_database.cc

 // Copyright (c) 2012 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.
 
 #include "chrome/browser/predictors/predictor_database.h"
 
 #include "base/bind.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/strings/stringprintf.h"
 #include "chrome/browser/predictors/autocomplete_action_predictor_table.h"
 #include "chrome/browser/predictors/logged_in_predictor_table.h"
-#include "chrome/browser/predictors/resource_prefetch_predictor.h"
-#include "chrome/browser/predictors/resource_prefetch_predictor_tables.h"
 #include "chrome/browser/prerender/prerender_field_trial.h"
 #include "chrome/browser/profiles/profile.h"
 #include "content/public/browser/browser_thread.h"
 #include "sql/connection.h"
 #include "sql/statement.h"
 
 using content::BrowserThread;
 
 namespace {
 
@@ skipping 18 matching lines @@
 
   // Opens the database file from the profile path. Separated from the
   // constructor to ease construction/destruction of this object on one thread
   // but database access on the DB thread.
   void Initialize();
   void LogDatabaseStats();  //  DB Thread.
 
   // Cancels pending DB transactions. Should only be called on the UI thread.
   void SetCancelled();
 
-  bool is_resource_prefetch_predictor_enabled_;
   base::FilePath db_path_;
   scoped_ptr<sql::Connection> db_;
 
   // TODO(shishir): These tables may not need to be refcounted. Maybe move them
   // to using a WeakPtr instead.
   scoped_refptr<AutocompleteActionPredictorTable> autocomplete_table_;
   scoped_refptr<LoggedInPredictorTable> logged_in_table_;
-  scoped_refptr<ResourcePrefetchPredictorTables> resource_prefetch_tables_;
 
   DISALLOW_COPY_AND_ASSIGN(PredictorDatabaseInternal);
 };
 
 
 PredictorDatabaseInternal::PredictorDatabaseInternal(Profile* profile)
     : db_path_(profile->GetPath().Append(kPredictorDatabaseName)),
       db_(new sql::Connection()),
       autocomplete_table_(new AutocompleteActionPredictorTable()),
-      logged_in_table_(new LoggedInPredictorTable()),
-      resource_prefetch_tables_(new ResourcePrefetchPredictorTables()) {
+      logged_in_table_(new LoggedInPredictorTable()) {
   db_->set_histogram_tag("Predictor");
-  ResourcePrefetchPredictorConfig config;
-  is_resource_prefetch_predictor_enabled_ =
-      IsSpeculativeResourcePrefetchingEnabled(profile, &config);
 }
 
 PredictorDatabaseInternal::~PredictorDatabaseInternal() {
   // The connection pointer needs to be deleted on the DB thread since there
   // might be a task in progress on the DB thread which uses this connection.
   if (BrowserThread::IsMessageLoopValid(BrowserThread::DB))
     BrowserThread::DeleteSoon(BrowserThread::DB, FROM_HERE, db_.release());
 }
 
 void PredictorDatabaseInternal::Initialize() {
   CHECK(BrowserThread::CurrentlyOn(BrowserThread::DB) ||
         !BrowserThread::IsMessageLoopValid(BrowserThread::DB));
   // TODO(tburkard): figure out if we need this.
   //  db_->set_exclusive_locking();
   bool success = db_->Open(db_path_);
 
   if (!success)
     return;
 
   autocomplete_table_->Initialize(db_.get());
   logged_in_table_->Initialize(db_.get());
-  resource_prefetch_tables_->Initialize(db_.get());
 
   LogDatabaseStats();
 }
 
 void PredictorDatabaseInternal::SetCancelled() {
   CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI) ||
         !BrowserThread::IsMessageLoopValid(BrowserThread::UI));
 
   autocomplete_table_->SetCancelled();
   logged_in_table_->SetCancelled();
-  resource_prefetch_tables_->SetCancelled();
 }
 
 void PredictorDatabaseInternal::LogDatabaseStats() {
   CHECK(BrowserThread::CurrentlyOn(BrowserThread::DB) ||
         !BrowserThread::IsMessageLoopValid(BrowserThread::DB));
 
   int64 db_size;
   bool success = base::GetFileSize(db_path_, &db_size);
   DCHECK(success) << "Failed to get file size for " << db_path_.value();
   UMA_HISTOGRAM_MEMORY_KB("PredictorDatabase.DatabaseSizeKB",
                           static_cast<int>(db_size / 1024));
 
   autocomplete_table_->LogDatabaseStats();
   logged_in_table_->LogDatabaseStats();
-  if (is_resource_prefetch_predictor_enabled_)
-    resource_prefetch_tables_->LogDatabaseStats();
 }
 
 PredictorDatabase::PredictorDatabase(Profile* profile)
     : db_(new PredictorDatabaseInternal(profile)) {
   BrowserThread::PostTask(BrowserThread::DB, FROM_HERE,
       base::Bind(&PredictorDatabaseInternal::Initialize, db_));
 }
 
 PredictorDatabase::~PredictorDatabase() {
 }
 
 void PredictorDatabase::Shutdown() {
   db_->SetCancelled();
 }
 
 scoped_refptr<AutocompleteActionPredictorTable>
     PredictorDatabase::autocomplete_table() {
   return db_->autocomplete_table_;
 }
 
 scoped_refptr<LoggedInPredictorTable>
     PredictorDatabase::logged_in_table() {
   return db_->logged_in_table_;
 }
 
-scoped_refptr<ResourcePrefetchPredictorTables>
-    PredictorDatabase::resource_prefetch_tables() {
-  return db_->resource_prefetch_tables_;
-}
-
 sql::Connection* PredictorDatabase::GetDatabase() {
   return db_->db_.get();
 }
 
 }  // namespace predictors