Implement UMA log throttling for cellular connections

chrome/browser/profiles/profile_io_data.cc

Index: chrome/browser/profiles/profile_io_data.cc
diff --git a/chrome/browser/profiles/profile_io_data.cc b/chrome/browser/profiles/profile_io_data.cc
index c4e0cd99ea99340dd0a1c09db223a65b0e501053..130b697009bbb8f8a21cba4b7d6ad2b1c69ef0a2 100644
--- a/chrome/browser/profiles/profile_io_data.cc
+++ b/chrome/browser/profiles/profile_io_data.cc
@@ -63,6 +63,7 @@
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data.h"
 #include "components/dom_distiller/core/url_constants.h"
 #include "components/metrics/metrics_pref_names.h"
+#include "components/metrics/metrics_service.h"
 #include "components/net_log/chrome_net_log.h"
 #include "components/policy/core/browser/url_blacklist_manager.h"
 #include "components/policy/core/common/cloud/policy_header_io_helper.h"
@@ -545,6 +546,10 @@ void ProfileIOData::InitializeOnUIThread(Profile* profile) {
   // are associated with each ResourceContext because we might post this
   // object to the IO thread after this function.
   BrowserContext::EnsureResourceContextInitialized(profile);
+
+  // Callback for updating data use prefs should be obtained on UI thread.
+  metrics_data_use_forwarder_ =
+      g_browser_process->metrics_service()->GetDataUseForwardingCallback();

[mmenke, 2016/04/04 17:26:23]

Can we just grab the callback from the IOThread?

Also, it's a bug that this is after setting initialialized_on_UI_thread to true
(And more importantly, after BrowserContext::EnsureResourceContextInitialized)

[gayane -on leave until 09-2017, 2016/04/05 14:26:46]

Did you mean to get from IOThread object ? If so, Done.

 }
 
 ProfileIOData::MediaRequestContext::MediaRequestContext() {
@@ -1016,14 +1021,13 @@ void ProfileIOData::Init(
   main_request_context_.reset(new net::URLRequestContext());
   extensions_request_context_.reset(new net::URLRequestContext());
 
-  scoped_ptr<ChromeNetworkDelegate> network_delegate(
-      new ChromeNetworkDelegate(
+  scoped_ptr<ChromeNetworkDelegate> network_delegate(new ChromeNetworkDelegate(
 #if defined(ENABLE_EXTENSIONS)
-          io_thread_globals->extension_event_router_forwarder.get(),
+      io_thread_globals->extension_event_router_forwarder.get(),
 #else
-          NULL,
+      NULL,
 #endif
-          &enable_referrers_));
+      &enable_referrers_, metrics_data_use_forwarder_));
 #if defined(ENABLE_EXTENSIONS)
   network_delegate->set_extension_info_map(
       profile_params_->extension_info_map.get());