Update histograms.xml wrt new V8.Compile{Cacheable,Noncacheable}MicroSeconds 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 e38cc51e239ad3a23cda03f8503c7f5c2a14d980..51302048cd285bb17c33c0a85da8f3130b067d39 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -39815,6 +39815,13 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   <summary>Time spent in V8 compiler (full codegen).</summary>
 </histogram>
 
+<histogram name="V8.CompileCacheableMicroseconds" units="microseconds">
+  <owner>yangguo@chromium.org</owner>
+  <summary>
+    Time spent compiling a script that may be subject to caching.
+  </summary>
+</histogram>
+
 <histogram name="V8.CompileDeserialize" units="milliseconds">
   <obsolete>
     This histogram has been replaced by V8.CompileDeserializeMicroSeconds.
@@ -39862,7 +39869,14 @@ Therefore, the affected-histogram name has to have at least one dot in it.
 <histogram name="V8.CompileMicroSeconds" units="microseconds">
   <owner>jochen@chromium.org</owner>
   <owner>yangguo@chromium.org</owner>
-  <summary>Time spent in V8 compiler (full codegen).</summary>
+  <summary>Time spent in V8 compiler (full codegen) excluding parser.</summary>
+</histogram>
+
+<histogram name="V8.CompileNoncacheableMicroSeconds" units="microseconds">
+  <owner>yangguo@chromium.org</owner>
+  <summary>
+    Time spent compiling a script that cannot be subject to caching.
+  </summary>
 </histogram>
 
 <histogram name="V8.CompileScript" units="milliseconds">