[NOT FOR LANDING] Detailed loading traces

chrome/browser/safe_browsing/local_database_manager.cc

Index: chrome/browser/safe_browsing/local_database_manager.cc
diff --git a/chrome/browser/safe_browsing/local_database_manager.cc b/chrome/browser/safe_browsing/local_database_manager.cc
index c49ed58666decbc8586d2e8cab928157d13e92dc..830b79af172d508c60b469a4d88a794213125009 100644
--- a/chrome/browser/safe_browsing/local_database_manager.cc
+++ b/chrome/browser/safe_browsing/local_database_manager.cc
@@ -18,6 +18,7 @@
 #include "base/stl_util.h"
 #include "base/strings/string_util.h"
 #include "base/thread_task_runner_handle.h"
+#include "base/trace_event/trace_event.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/prerender/prerender_field_trial.h"
@@ -315,6 +316,10 @@ LocalSafeBrowsingDatabaseManager::LocalSafeBrowsingDatabaseManager(
 }
 
 LocalSafeBrowsingDatabaseManager::~LocalSafeBrowsingDatabaseManager() {
+  TRACE_EVENT0(
+      "toplevel",
+      "LocalSafeBrowsingDatabaseManager::~LocalSafeBrowsingDatabaseManager");
+
   // The DCHECK is disabled due to crbug.com/438754.
   // DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
@@ -505,6 +510,7 @@ bool LocalSafeBrowsingDatabaseManager::IsCsdWhitelistKillSwitchOn() {
 
 bool LocalSafeBrowsingDatabaseManager::CheckBrowseUrl(const GURL& url,
                                                  Client* client) {
+  TRACE_EVENT0("toplevel", "LocalSafeBrowsingDatabaseManager::CheckBrowseUrl");
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   if (!enabled_)
     return true;
@@ -551,13 +557,17 @@ bool LocalSafeBrowsingDatabaseManager::CheckBrowseUrl(const GURL& url,
   // by default rather than building it here.
   std::vector<SBPrefix> prefix_hits(browse_prefix_hits.size() +
                                     unwanted_prefix_hits.size());
-  std::merge(browse_prefix_hits.begin(),
-             browse_prefix_hits.end(),
-             unwanted_prefix_hits.begin(),
-             unwanted_prefix_hits.end(),
-             prefix_hits.begin());
-  prefix_hits.erase(std::unique(prefix_hits.begin(), prefix_hits.end()),
-                    prefix_hits.end());
+  {
+    TRACE_EVENT0(
+        "toplevel",
+        "LocalSafeBrowsingDatabaseManager::CheckBrowseUrl::MergeAndErase");
+
+    std::merge(browse_prefix_hits.begin(), browse_prefix_hits.end(),
+               unwanted_prefix_hits.begin(), unwanted_prefix_hits.end(),
+               prefix_hits.begin());
+    prefix_hits.erase(std::unique(prefix_hits.begin(), prefix_hits.end()),
+                      prefix_hits.end());
+  }
 
   UMA_HISTOGRAM_TIMES("SB2.FilterCheck", base::TimeTicks::Now() - start);