Periodically remove old pending navigation entries.

chrome/browser/data_use_measurement/chrome_data_use_ascriber.cc

Index: chrome/browser/data_use_measurement/chrome_data_use_ascriber.cc
diff --git a/chrome/browser/data_use_measurement/chrome_data_use_ascriber.cc b/chrome/browser/data_use_measurement/chrome_data_use_ascriber.cc
index a41f0296c23da9b94cc5a08cd2084f2128059a3c..dddd21ebce12827cbb6e2696f9253df1e7dfdcc3 100644
--- a/chrome/browser/data_use_measurement/chrome_data_use_ascriber.cc
+++ b/chrome/browser/data_use_measurement/chrome_data_use_ascriber.cc
@@ -16,8 +16,14 @@
 #include "content/public/common/browser_side_navigation_policy.h"
 #include "net/url_request/url_request.h"
 
-namespace data_use_measurement {
+namespace {
+const base::TimeDelta kDiscardPendingNavigationsThreshold =
+    base::TimeDelta::FromSeconds(5);
+const base::TimeDelta kDiscardPendingNavigationsInterval =
+    base::TimeDelta::FromSeconds(10);
+}
 
+namespace data_use_measurement {
 // static
 const void* ChromeDataUseAscriber::DataUseRecorderEntryAsUserData::
     kUserDataKey = static_cast<void*>(
@@ -36,7 +42,9 @@ ChromeDataUseAscriber::ChromeDataUseAscriber() {
 
 ChromeDataUseAscriber::~ChromeDataUseAscriber() {
   DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
-  DCHECK_EQ(0u, data_use_recorders_.size());
+  DCHECK_EQ(0u, render_frame_data_use_map_.size());
+  DCHECK_EQ(pending_navigation_data_use_map_.size(),
+            data_use_recorders_.size());
 }
 
 DataUseRecorder* ChromeDataUseAscriber::GetDataUseRecorder(
@@ -96,6 +104,8 @@ void ChromeDataUseAscriber::OnBeforeUrlRequest(net::URLRequest* request) {
                        new DataUseRecorderEntryAsUserData(entry));
   pending_navigation_data_use_map_.insert(
       std::make_pair(request_info->GetGlobalRequestID(), entry));
+
+  DeleteOldPendingNavigationEntries(base::Time::Now());
 }
 
 void ChromeDataUseAscriber::OnUrlRequestDestroyed(net::URLRequest* request) {
@@ -190,4 +200,26 @@ ChromeDataUseAscriber::CreateURLRequestClassifier() const {
   return base::MakeUnique<ContentURLRequestClassifier>();
 }
 
+void ChromeDataUseAscriber::DeleteOldPendingNavigationEntries(base::Time now) {
+  if (last_pending_navigations_discard_time_ >
+      now + kDiscardPendingNavigationsInterval) {
+    return;
+  }
+  last_pending_navigations_discard_time_ = now;
+
+  for (auto iter = pending_navigation_data_use_map_.begin();
+       iter != pending_navigation_data_use_map_.end();) {
+    DataUseRecorderEntry entry = iter->second;
+    DataUseRecorder* recorder = (*entry).get();
+    const DataUse& data_use = (*entry)->data_use();
+    if (recorder->IsDataUseComplete() &&
+        data_use.start_time() <= now - kDiscardPendingNavigationsThreshold) {
+      data_use_recorders_.erase(entry);
+      iter = pending_navigation_data_use_map_.erase(iter);
+    } else {
+      iter++;
+    }
+  }
+}
+
 }  // namespace data_use_measurement