Remove one thread hop while fetching matching rules

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 <utility>
 
 #include "base/containers/hash_tables.h"
 #include "base/message_loop/message_loop.h"
@@ skipping 115 matching lines @@
     "ExternalDataUseObserver";
 
 // static
 const size_t ExternalDataUseObserver::kMaxBufferSize = 100;
 
 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()),
       last_data_report_submitted_ticks_(base::TimeTicks()),
       pending_report_bytes_(0),
       ui_task_runner_(ui_task_runner),
       previous_report_time_(base::Time::Now()),
       last_matching_rules_fetch_time_(base::TimeTicks::Now()),
-      external_data_use_observer_bridge_(new ExternalDataUseObserverBridge()),
       total_bytes_buffered_(0),
       fetch_matching_rules_duration_(
           base::TimeDelta::FromSeconds(GetFetchMatchingRulesDurationSeconds())),
       data_use_report_min_bytes_(GetMinBytes()),
       data_report_submit_timeout_(
           base::TimeDelta::FromMilliseconds(GetDataReportSubmitTimeoutMsec())),
 #if defined(OS_ANDROID)
       app_state_listener_(new base::android::ApplicationStatusListener(
           base::Bind(&ExternalDataUseObserver::OnApplicationStateChange,
                      base::Unretained(this)))),
 #endif
       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_);
   DCHECK(last_data_report_submitted_ticks_.is_null());
 
   ui_task_runner_->PostTask(FROM_HERE,
                             base::Bind(&DataUseTabModel::InitOnUIThread,
                                        base::Unretained(data_use_tab_model_),
-                                       io_task_runner, GetWeakPtr()));
+                                       external_data_use_observer_bridge_));
 
-  // Initialize the ExternalDataUseObserverBridge object. Initialization will
-  // also trigger the fetching of matching rules. 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.
+  // 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_));
 }
 
 ExternalDataUseObserver::~ExternalDataUseObserver() {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   if (registered_as_data_use_observer_)
     data_use_aggregator_->RemoveObserver(this);
 
+  // Delete |data_use_tab_model_| on the UI thread. |data_use_tab_model_| should
+  // be deleted before |external_data_use_observer_bridge_|.
+  if (!ui_task_runner_->DeleteSoon(FROM_HERE, data_use_tab_model_)) {
+    NOTIMPLEMENTED() << " DataUseTabModel was not deleted successfully";
+  }
+
   // Delete |external_data_use_observer_bridge_| on the UI thread.
   if (!ui_task_runner_->DeleteSoon(FROM_HERE,
                                    external_data_use_observer_bridge_)) {
     NOTIMPLEMENTED()
         << " ExternalDataUseObserverBridge was not deleted successfully";
   }
-
-  // Delete |data_use_tab_model_| on the UI thread.
-  if (!ui_task_runner_->DeleteSoon(FROM_HERE, data_use_tab_model_)) {
-    NOTIMPLEMENTED() << " DataUseTabModel was not deleted successfully";
-  }
 }
 
 void ExternalDataUseObserver::OnReportDataUseDone(bool success) {
   DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK(!last_data_report_submitted_ticks_.is_null());
 
   if (success) {
     RecordDataUsageReportSubmission(DATAUSAGE_REPORT_SUBMISSION_SUCCESSFUL,
                                     pending_report_bytes_);
   } else {
@@ skipping 236 matching lines @@
   size_t hash = 1;
   hash = hash * 23 + hash_function(k.label);
   hash = hash * 43 + k.connection_type;
   hash = hash * 83 + hash_function(k.mcc_mnc);
   return hash;
 }
 
 }  // namespace android
 
 }  // namespace chrome