Extensions: Add metrics to distinguish between the different kinds of declarative API function call…

tools/metrics/histograms/enums.xml

Index: tools/metrics/histograms/enums.xml
diff --git a/tools/metrics/histograms/enums.xml b/tools/metrics/histograms/enums.xml
index a436e7059964d95eb88fe0ec9442fff5977e65e9..3d3b4c75acafd9ee0428ef19c1c0bcea7df4020d 100644
--- a/tools/metrics/histograms/enums.xml
+++ b/tools/metrics/histograms/enums.xml
@@ -6856,6 +6856,18 @@ uploading your change for review.  These are checked by presubmit scripts.
   <int value="40" label="LargeIconService"/>
 </enum>
 
+<enum name="DeclarativeAPIFunctionType" type="int">
+  <int value="0" label="kDeclarativeContentAddRules"/>
+  <int value="1" label="kDeclarativeContentRemoveRules"/>
+  <int value="2" label="kDeclarativeContentGetRules"/>
+  <int value="3" label="kDeclarativeWebRequestAddRules"/>
+  <int value="4" label="kDeclarativeWebRequestRemoveRules"/>
+  <int value="5" label="kDeclarativeWebRequestGetRules"/>
+  <int value="6" label="kDeclarativeWebRequestWebviewAddRules"/>
+  <int value="7" label="kDeclarativeWebRequestWebviewRemoveRules"/>
+  <int value="8" label="kDeclarativeWebRequestWebviewGetRules"/>
+</enum>
+
 <enum name="DecodedImageOrientation" type="int">
   <int value="0" label="Unknown"/>
   <int value="1" label="Top Left"/>