Make DataUseTabModel and DataUseMatcher more independent

chrome/browser/android/data_usage/external_data_use_observer.cc

 // Copyright 2015 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/android/data_usage/external_data_use_observer.h"
 
+#include "base/bind.h"
 #include "base/metrics/field_trial.h"
 #include "base/single_thread_task_runner.h"
 #include "base/strings/string_number_conversions.h"
 #include "chrome/browser/android/data_usage/data_use_tab_model.h"
 #include "chrome/browser/android/data_usage/external_data_use_observer_bridge.h"
 #include "chrome/browser/android/data_usage/external_data_use_reporter.h"
 #include "components/data_usage/core/data_use.h"
 #include "components/variations/variations_associated_data.h"
 #include "content/public/browser/browser_thread.h"
 
@@ skipping 27 matching lines @@
 // static
 const char ExternalDataUseObserver::kExternalDataUseObserverFieldTrial[] =
     "ExternalDataUseObserver";
 
 ExternalDataUseObserver::ExternalDataUseObserver(
     data_usage::DataUseAggregator* data_use_aggregator,
     const scoped_refptr<base::SingleThreadTaskRunner>& io_task_runner,
     const scoped_refptr<base::SingleThreadTaskRunner>& ui_task_runner)
     : data_use_aggregator_(data_use_aggregator),
       external_data_use_observer_bridge_(new ExternalDataUseObserverBridge()),
-      data_use_tab_model_(new DataUseTabModel()),
+      // It is okay to use  base::Unretained for the callbacks, since
+      // |external_data_use_observer_bridge_| is owned by |this|, and is
+      // destroyed on UI thread after |this| and |data_use_tab_model_| are
+      // destroyed.
+      data_use_tab_model_(new DataUseTabModel(
+          base::Bind(&ExternalDataUseObserverBridge::FetchMatchingRules,
+                     base::Unretained(external_data_use_observer_bridge_)),
+          base::Bind(
+              &ExternalDataUseObserverBridge::ShouldRegisterAsDataUseObserver,
+              base::Unretained(external_data_use_observer_bridge_)))),
       external_data_use_reporter_(
           new ExternalDataUseReporter(kExternalDataUseObserverFieldTrial,
                                       data_use_tab_model_,
                                       external_data_use_observer_bridge_)),
       ui_task_runner_(ui_task_runner),
       last_matching_rules_fetch_time_(base::TimeTicks::Now()),
       fetch_matching_rules_duration_(
           base::TimeDelta::FromSeconds(GetFetchMatchingRulesDurationSeconds())),
       registered_as_data_use_observer_(false),
       weak_factory_(this) {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
   DCHECK(data_use_aggregator_);
   DCHECK(io_task_runner);
   DCHECK(ui_task_runner_);
 
   // Initialize the ExternalDataUseReporter object. It is okay to use
   // base::Unretained here since |external_data_use_reporter_| is owned by
   // |this|, and is destroyed on UI thread when |this| is destroyed.
   ui_task_runner_->PostTask(
       FROM_HERE, base::Bind(&ExternalDataUseReporter::InitOnUIThread,
                             base::Unretained(external_data_use_reporter_)));
 
-  ui_task_runner_->PostTask(FROM_HERE,
-                            base::Bind(&DataUseTabModel::InitOnUIThread,
-                                       base::Unretained(data_use_tab_model_),
-                                       external_data_use_observer_bridge_));
-
   // Initialize the ExternalDataUseObserverBridge object. It is okay to use
   // base::Unretained here since |external_data_use_observer_bridge_| is owned
   // by |this|, and is destroyed on UI thread when |this| is destroyed.
   ui_task_runner_->PostTask(
       FROM_HERE,
       base::Bind(&ExternalDataUseObserverBridge::Init,
                  base::Unretained(external_data_use_observer_bridge_),
                  io_task_runner, GetWeakPtr(), data_use_tab_model_));
 }
 
@@ skipping 91 matching lines @@
 }
 
 DataUseTabModel* ExternalDataUseObserver::GetDataUseTabModel() const {
   DCHECK(thread_checker_.CalledOnValidThread());
   return data_use_tab_model_;
 }
 
 }  // namespace android
 
 }  // namespace chrome