LevelDB storage for data reduction proxy to store data usage stats.

chrome/browser/net/spdyproxy/data_reduction_proxy_chrome_settings.cc

Index: chrome/browser/net/spdyproxy/data_reduction_proxy_chrome_settings.cc
diff --git a/chrome/browser/net/spdyproxy/data_reduction_proxy_chrome_settings.cc b/chrome/browser/net/spdyproxy/data_reduction_proxy_chrome_settings.cc
index 0c43b511fd5ed6e32bf212e872276a7f181a9f41..4b332ec96bdd54002bbaec53aaa9e7ee4722f8eb 100644
--- a/chrome/browser/net/spdyproxy/data_reduction_proxy_chrome_settings.cc
+++ b/chrome/browser/net/spdyproxy/data_reduction_proxy_chrome_settings.cc
@@ -7,6 +7,7 @@
 #include <string>
 
 #include "base/base64.h"
+#include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/prefs/pref_service.h"
@@ -24,6 +25,7 @@
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data.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_reduction_proxy_store_impl.h"
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_params.h"
 #include "net/base/host_port_pair.h"
 #include "net/proxy/proxy_config.h"
@@ -175,7 +177,9 @@ void DataReductionProxyChromeSettings::InitDataReductionProxySettings(
     data_reduction_proxy::DataReductionProxyIOData* io_data,
     PrefService* profile_prefs,
     net::URLRequestContextGetter* request_context_getter,
-    const scoped_refptr<base::SingleThreadTaskRunner>& ui_task_runner) {
+    const base::FilePath& profile_path,
+    const scoped_refptr<base::SingleThreadTaskRunner>& ui_task_runner,
+    const scoped_refptr<base::SingleThreadTaskRunner>& db_task_runner) {
 #if defined(OS_ANDROID) || defined(OS_IOS)
   // On mobile we write Data Reduction Proxy prefs directly to the pref service.
   // On desktop we store Data Reduction Proxy prefs in memory, writing to disk
@@ -187,10 +191,18 @@ void DataReductionProxyChromeSettings::InitDataReductionProxySettings(
   base::TimeDelta commit_delay = base::TimeDelta::FromMinutes(60);
 #endif
 
+  scoped_refptr<data_reduction_proxy::DataReductionProxyStoreImpl> store(

[bengr, 2015/06/25 23:22:54]

So the store is created on UI and initialzed on DB? Can DB outlive UI?

Also, our UI-to-IO thread hopping code in in DRPService. It might make sense to
put our UI-to-DB posts there too.

[Not at Google. Contact bengr, 2015/06/29 20:53:26]

UI thread outlives DB thread.

For DB thread hops we don't use weak pointers so a similar structure does not
get anything functionally.

We could do this for stylistic reasons, but DRPService seems like the wrong
place. I could add a new class -- DRPDBService say -- which will post to DB
thread. However, currently compression stats and here are the only places such
posts would happen. How about waiting until there is a usecase outside of
compression stats?

+      new data_reduction_proxy::DataReductionProxyStoreImpl(profile_path));
+  db_task_runner->PostTask(
+      FROM_HERE, base::Bind(&data_reduction_proxy::DataReductionProxyStoreImpl::
+                                InitializeOnDBThread,
+                            store));
+
   scoped_ptr<data_reduction_proxy::DataReductionProxyCompressionStats>
-      compression_stats = make_scoped_ptr(
+      compression_stats(
           new data_reduction_proxy::DataReductionProxyCompressionStats(
-              profile_prefs, ui_task_runner, commit_delay));
+              profile_prefs, ui_task_runner, db_task_runner, store,
+              commit_delay));
   scoped_ptr<data_reduction_proxy::DataReductionProxyService> service =
       make_scoped_ptr(new data_reduction_proxy::DataReductionProxyService(
           compression_stats.Pass(), this, profile_prefs, request_context_getter,