Add high-precision timing histograms.

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 50c656f7c7a6c30490e717e4c25ee2631bfd9119..39fae5928fe4a98a10b18115b33faee69138a890 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -63089,6 +63089,24 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <summary>Microseconds spent in Document::updateStyle.</summary>
 </histogram>
 
+<histogram name="SubresourceFilter.DocumentLoad.Activation.CPUDuration"
+    units="microseconds">
+  <owner>pkalinnikov@chromium.org</owner>
+  <summary>
+    Records how much thread CPU time it takes to decide whether subresource
+    filtering should be activated for a main frame or subframe.
+  </summary>
+</histogram>
+
+<histogram name="SubresourceFilter.DocumentLoad.Activation.WallDuration"
+    units="microseconds">
+  <owner>pkalinnikov@chromium.org</owner>
+  <summary>
+    Records how long it takes to decide whether subresource filtering should be
+    activated for a main frame or subframe.
+  </summary>
+</histogram>
+
 <histogram name="SubresourceFilter.DocumentLoad.ActivationState"
     enum="SubresourceFilterActivationState">
   <owner>engedy@chromium.org</owner>
@@ -63152,6 +63170,39 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram
+    name="SubresourceFilter.DocumentLoad.SubresourceSums.Evaluation.CPUDuration"
+    units="ms">
+  <owner>pkalinnikov@chromium.org</owner>
+  <summary>
+    Whenever a document load is finished in a main frame or subframe with
+    subresource filtering activated, records the total thread CPU time spent on
+    processing subresource requests in allowLoad.
+  </summary>
+</histogram>
+
+<histogram
+    name="SubresourceFilter.DocumentLoad.SubresourceSums.Evaluation.WallDuration"
+    units="ms">
+  <owner>pkalinnikov@chromium.org</owner>
+  <summary>
+    Whenever a document load is finished in a main frame or subframe with
+    subresource filtering activated, records the total real time spent on
+    processing subresource requests in allowLoad, including the time spent on
+    waiting or being descheduled.
+  </summary>
+</histogram>
+
+<histogram name="SubresourceFilter.IndexRuleset.CPUDuration" units="ms">
+  <owner>pkalinnikov@chromium.org</owner>
+  <summary>
+    The total CPU time it took to parse and index all rules. Does not include
+    time when the indexing thread was not doing actual work, e.g. waiting for
+    I/O or being descheduled. Recorded every time the RulesetService kicks off a
+    ruleset indexing process.
+  </summary>
+</histogram>
+
 <histogram name="SubresourceFilter.IndexRuleset.NumUnsupportedRules"
     units="rules">
   <owner>engedy@chromium.org</owner>
@@ -63188,6 +63239,24 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="SubresourceFilter.SubresourceLoad.Evaluation.CPUDuration"
+    units="microseconds">
+  <owner>pkalinnikov@chromium.org</owner>
+  <summary>
+    Whenever a subresource of a document is evaluated against the ruleset,
+    records the thread CPU time spent on calculating.
+  </summary>
+</histogram>
+
+<histogram name="SubresourceFilter.SubresourceLoad.Evaluation.WallDuration"
+    units="microseconds">
+  <owner>pkalinnikov@chromium.org</owner>
+  <summary>
+    Whenever a subresource of a document is evaluated against the ruleset,
+    records how much time was spent on calculating.
+  </summary>
+</histogram>
+
 <histogram name="SubresourceFilter.WriteRuleset.ReplaceFileError"
     enum="PlatformFileError">
   <owner>engedy@chromium.org</owner>