Disable data use ascriber if data saver is not enabled.

This is guarded behind a field trial, and is the last killswitch option.

Bug: 781189
Change-Id: I22a25ff6a2629ca8b59aef727c54e2f491cb4771
Reviewed-on: https://chromium-review.googlesource.com/872074
Commit-Queue: Tarun Bansal <tbansal@chromium.org>
Reviewed-by: Ryan Sturm <ryansturm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#530449}

chrome/browser/data_use_measurement/chrome_data_use_ascriber.cc

@@ -28,6 +28,9 @@
 
 namespace data_use_measurement {
 
+const base::Feature kDisableAscriberIfDataSaverDisabled{
+    "DisableAscriberIfDataSaverDisabled", base::FEATURE_DISABLED_BY_DEFAULT};
+
 // static
 const void* const ChromeDataUseAscriber::DataUseRecorderEntryAsUserData::
     kDataUseAscriberUserDataKey =
@@ -194,6 +197,9 @@ void ChromeDataUseAscriber::OnUrlRequestCompleted(net::URLRequest* request,
   DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
   DCHECK(request);
 
+  if (IsDisabled())
+    return;
+
   const DataUseRecorderEntry entry = GetDataUseRecorderEntry(request);
 
   if (entry == data_use_recorders_.end())
@@ -214,6 +220,11 @@ void ChromeDataUseAscriber::OnUrlRequestCompletedOrDestroyed(
   DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
   DCHECK(request);
 
+  if (IsDisabled())
+    return;
+
+  DCHECK(request);
+
   const DataUseRecorderEntry entry = GetDataUseRecorderEntry(request);
 
   if (entry == data_use_recorders_.end())
@@ -275,6 +286,8 @@ void ChromeDataUseAscriber::RenderFrameCreated(int render_process_id,
                                                int main_render_process_id,
                                                int main_render_frame_id) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+  if (IsDisabled())
+    return;
 
   const auto render_frame =
       RenderFrameHostID(render_process_id, render_frame_id);
@@ -305,6 +318,9 @@ void ChromeDataUseAscriber::RenderFrameDeleted(int render_process_id,
                                                int main_render_frame_id) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
 
+  if (IsDisabled())
+    return;
+
   RenderFrameHostID key(render_process_id, render_frame_id);
 
   if (main_render_process_id == -1 && main_render_frame_id == -1) {
@@ -327,6 +343,8 @@ void ChromeDataUseAscriber::ReadyToCommitMainFrameNavigation(
     int render_process_id,
     int render_frame_id) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+  if (IsDisabled())
+    return;
 
   main_render_frame_entry_map_
       .find(RenderFrameHostID(render_process_id, render_frame_id))
@@ -341,6 +359,8 @@ void ChromeDataUseAscriber::DidFinishMainFrameNavigation(
     uint32_t page_transition,
     base::TimeTicks time) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+  if (IsDisabled())
+    return;
 
   RenderFrameHostID main_frame(render_process_id, render_frame_id);
 
@@ -528,6 +548,8 @@ void ChromeDataUseAscriber::WasShownOrHidden(int main_render_process_id,
                                              int main_render_frame_id,
                                              bool visible) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+  if (IsDisabled())
+    return;
 
   auto main_frame_it = main_render_frame_entry_map_.find(
       RenderFrameHostID(main_render_process_id, main_render_frame_id));
@@ -543,6 +565,8 @@ void ChromeDataUseAscriber::RenderFrameHostChanged(int old_render_process_id,
                                                    int new_render_process_id,
                                                    int new_render_frame_id) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+  if (IsDisabled())
+    return;
 
   auto old_frame_iter = main_render_frame_entry_map_.find(
       RenderFrameHostID(old_render_process_id, old_render_frame_id));
@@ -563,4 +587,18 @@ void ChromeDataUseAscriber::RenderFrameHostChanged(int old_render_process_id,
   }
 }
 
+bool ChromeDataUseAscriber::IsDisabled() const {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+
+  // TODO(rajendrant): https://crbug.com/753559. Fix platform specific race
+  // conditions and re-enable.
+  return base::FeatureList::IsEnabled(kDisableAscriberIfDataSaverDisabled) &&
+         disable_ascriber_;
+}
+
+void ChromeDataUseAscriber::DisableAscriber() {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+  disable_ascriber_ = true;
+}
+
 }  // namespace data_use_measurement

chrome/browser/data_use_measurement/chrome_data_use_ascriber.h

@@ -12,6 +12,7 @@
 #include <tuple>
 #include <utility>
 
+#include "base/feature_list.h"
 #include "base/hash.h"
 #include "base/macros.h"
 #include "base/supports_user_data.h"
@@ -27,6 +28,9 @@ class RenderFrameHost;
 
 namespace data_use_measurement {
 
+// Disables data use ascriber if data saver is disabled.
+extern const base::Feature kDisableAscriberIfDataSaverDisabled;
+
 class URLRequestClassifier;
 
 // Browser implementation of DataUseAscriber. Maintains a list of
@@ -181,6 +185,11 @@ class ChromeDataUseAscriber : public DataUseAscriber {
   void AscribeRecorderWithRequest(net::URLRequest* request,
                                   DataUseRecorderEntry entry);
 
+  void DisableAscriber() override;
+
+  // Returns true if data use ascriber is disabled.
+  bool IsDisabled() const;
+
   // Owner for all instances of DataUseRecorder. An instance is kept in this
   // list if any entity (render frame hosts, URLRequests, pending navigations)
   // that ascribe data use to the instance exists, and deleted when all
@@ -206,6 +215,10 @@ class ChromeDataUseAscriber : public DataUseAscriber {
   // Detects heavy pages. Can be null when the feature is disabled.
   std::unique_ptr<DataUseAscriber::PageLoadObserver> page_capping_observer_;
 
+  // True if the dtaa use ascriber should be disabled. The ascriber is enabled
+  // by default.
+  bool disable_ascriber_ = false;
+
   DISALLOW_COPY_AND_ASSIGN(ChromeDataUseAscriber);
 };
 

components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data.cc

@@ -419,6 +419,11 @@ void DataReductionProxyIOData::SetDataUseAscriber(
   DCHECK(data_use_ascriber);
   data_use_observer_.reset(
       new DataReductionProxyDataUseObserver(this, data_use_ascriber));
+
+  // Disable data use ascriber when data saver is not enabled.
+  if (!IsEnabled()) {
+    data_use_ascriber->DisableAscriber();
+  }
 }
 
 void DataReductionProxyIOData::SetPreviewsDecider(

components/data_use_measurement/core/data_use_ascriber.cc

@@ -66,4 +66,6 @@ void DataUseAscriber::OnUrlRequestDestroyed(net::URLRequest* request) {
   recorder->OnUrlRequestDestroyed(request);
 }
 
+void DataUseAscriber::DisableAscriber() {}
+
 }  // namespace data_use_measurement

components/data_use_measurement/core/data_use_ascriber.h

@@ -109,6 +109,9 @@ class DataUseAscriber {
   virtual void OnUrlRequestCompleted(net::URLRequest* request, bool started);
   virtual void OnUrlRequestDestroyed(net::URLRequest* request);
 
+  // Disables data use ascriber.
+  virtual void DisableAscriber();
+
  protected:
   base::ObserverList<PageLoadObserver> observers_;