Make module enumeration a low priority background task.

tools/metrics/histograms/histograms.xml

Index: tools/metrics/histograms/histograms.xml
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index 35fc67d767868d234e086d927a4316f80c21ab2a..d3c3b8dfc53bff716d105b5a33f5d99f39240c93 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -6804,6 +6804,60 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Conflicts.ConfirmedBadModules" units="modules">
+  <owner>chrisha@chromium.org</owner>
+  <summary>
+    The number of confirmed bad modules found during module enumeration.
+  </summary>
+</histogram>
+
+<histogram name="Conflicts.EnumerateLoadedModules" units="ms">
+  <owner>chrisha@chromium.org</owner>
+  <summary>
+    The length of time it takes to enumerate the loaded modules in the browser
+    process.
+  </summary>
+</histogram>
+
+<histogram name="Conflicts.EnumerateShellExtensions" units="ms">
+  <owner>chrisha@chromium.org</owner>
+  <summary>
+    The length of time it takes to enumerate the shell extensions.
+  </summary>
+</histogram>
+
+<histogram name="Conflicts.EnumerateWinsockModules" units="ms">
+  <owner>chrisha@chromium.org</owner>
+  <summary>
+    The length of time it takes to enumerate the Winsock LSP modules.
+  </summary>
+</histogram>
+
+<histogram name="Conflicts.EnumerationInspectionTime" units="ms">
+  <owner>chrisha@chromium.org</owner>
+  <summary>
+    The cumulative length of time it takes to inspect all modules on disk,
+    extracting their certificates and version information. This work is actually
+    spread out over a much longer period of time so as not to impact the user.
+  </summary>
+</histogram>
+
+<histogram name="Conflicts.EnumerationTotalTime" units="ms">
+  <owner>chrisha@chromium.org</owner>
+  <summary>
+    The cumulative length of time it takes to enumerate and inspect all modules.
+    This work is actually spread out over a much longer period of time so as not
+    to impact the user.
+  </summary>
+</histogram>
+
+<histogram name="Conflicts.SuspectedBadModules" units="modules">
+  <owner>chrisha@chromium.org</owner>
+  <summary>
+    The number of suspected bad modules found during module enumeration.
+  </summary>
+</histogram>
+
 <histogram name="ConnectivityDiagnostics.ChromeOsSignalStrength" units="%">
   <owner>ebeach@google.com</owner>
   <summary>