Expose API to store and load data usage stats from UI task runner.

android_webview/browser/aw_browser_context.cc

Index: android_webview/browser/aw_browser_context.cc
diff --git a/android_webview/browser/aw_browser_context.cc b/android_webview/browser/aw_browser_context.cc
index fbdb5cd0be07b8b649e0874b5a344b756f76489b..00c59fac1e0fafd7c0819b1ac583e6a0807f9b3f 100644
--- a/android_webview/browser/aw_browser_context.cc
+++ b/android_webview/browser/aw_browser_context.cc
@@ -25,6 +25,7 @@
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_prefs.h"
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_service.h"
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_settings.h"
+#include "components/data_reduction_proxy/core/browser/data_store.h"
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_params.h"
 #include "components/user_prefs/user_prefs.h"
 #include "components/visitedlink/browser/visitedlink_master.h"
@@ -167,13 +168,21 @@ void AwBrowserContext::PreMainMessageLoopRun() {
           GetUserAgent()));
   data_reduction_proxy_settings_.reset(
       new data_reduction_proxy::DataReductionProxySettings());
+  scoped_ptr<data_reduction_proxy::DataStore> store(
+      new data_reduction_proxy::DataStore());
+  base::SequencedWorkerPool* pool = BrowserThread::GetBlockingPool();
+  scoped_refptr<base::SequencedTaskRunner> db_task_runner =
+      pool->GetSequencedTaskRunnerWithShutdownBehavior(
+          pool->GetSequenceToken(),
+          base::SequencedWorkerPool::SKIP_ON_SHUTDOWN);
   data_reduction_proxy_service_.reset(
       new data_reduction_proxy::DataReductionProxyService(
           scoped_ptr<
               data_reduction_proxy::DataReductionProxyCompressionStats>(),
           data_reduction_proxy_settings_.get(), nullptr,
-          GetAwURLRequestContext(),
-          BrowserThread::GetMessageLoopProxyForThread(BrowserThread::IO)));
+          GetAwURLRequestContext(), store.Pass(),
+          BrowserThread::GetMessageLoopProxyForThread(BrowserThread::IO),
+          db_task_runner));
   data_reduction_proxy_io_data_->SetDataReductionProxyService(
       data_reduction_proxy_service_->GetWeakPtr());
 
@@ -383,10 +392,15 @@ void AwBrowserContext::CreateDataReductionProxyStatisticsIfNecessary() {
     return;
   // We don't care about commit_delay for now. It is just a dummy value.
   base::TimeDelta commit_delay = base::TimeDelta::FromMinutes(60);
+  base::SequencedWorkerPool* pool = BrowserThread::GetBlockingPool();
+  scoped_refptr<base::SequencedTaskRunner> db_task_runner =
+      pool->GetSequencedTaskRunnerWithShutdownBehavior(
+          pool->GetSequenceToken(),
+          base::SequencedWorkerPool::SKIP_ON_SHUTDOWN);

[jeremyim, 2015/07/14 23:06:03]

This shouldn't be necessary, as drp_service_ already has the db_task_runner.

[Not at Google. Contact bengr, 2015/07/15 00:08:17]

Done.

   data_reduction_proxy_service->EnableCompressionStatisticsLogging(
       user_pref_service_.get(),
       BrowserThread::GetMessageLoopProxyForThread(BrowserThread::UI),
-      commit_delay);
+      db_task_runner, commit_delay);
 }
 
 }  // namespace android_webview