[Tentaive patch for discussion] Add Purge+Suspend metrics as UMA.

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 c872bf40a02ce1cc860d47dfa56400de6b63cd42..dd57a47b81aa7a88635f5651f7b51639cc6a1d3d 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -25084,6 +25084,71 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <summary>The current process limit.  Recorded once per UMA ping.</summary>
 </histogram>
 
+<histogram name="Memory.PurgeAndSuspend.BlinkGCKB" units="KB">
+  <owner>tasak@google.com</owner>
+  <summary>
+    The total allocated object size of BilnkGC allocator when purging and
+    suspending a backgrounded renderer. Note: this metrics is for A/B testing.
+  </summary>
+</histogram>
+
+<histogram name="Memory.PurgeAndSuspend.DiscardableKB" units="KB">
+  <owner>tasak@google.com</owner>
+  <summary>
+    The discardable memory usage of a backgrounded renderer when purging and
+    suspending the renderer. Note: this metrics is for A/B testing.
+  </summary>
+</histogram>
+
+<histogram name="Memory.PurgeAndSuspend.MallocKB" units="KB">
+  <owner>tasak@google.com</owner>
+  <summary>
+    The malloc memory usage of a backgrounded renderer when purging and
+    suspending the renderer. Note: this metrics is for A/B testing.
+  </summary>
+</histogram>
+
+<histogram name="Memory.PurgeAndSuspend.PartitionAllocKB" units="KB">
+  <owner>tasak@google.com</owner>
+  <summary>
+    The total allocated object size of partition alloc when purging and
+    suspending a backgrounded renderer.
+  </summary>
+</histogram>
+
+<histogram name="Memory.PurgeAndSuspend.PrivateBytesKB" units="KB">
+  <owner>tasak@google.com</owner>
+  <summary>
+    The private bytes of a backgrounded renderer when purging and suspending the
+    renderer.
+  </summary>
+</histogram>
+
+<histogram name="Memory.PurgeAndSuspend.SharedBytesKB" units="KB">
+  <owner>tasak@google.com</owner>
+  <summary>
+    The shared bytes of a backgrounded renderer when purging and suspending the
+    renderer.
+  </summary>
+</histogram>
+
+<histogram name="Memory.PurgeAndSuspend.TotalAllocatedKB" units="KB">
+  <owner>tasak@google.com</owner>
+  <summary>
+    The sum of PartitionAlloc, malloc, discardable, v8 and BlinkGC usage when
+    purging and suspending a backgrounded renderer. Note: this metrics is for
+    A/B testing.
+  </summary>
+</histogram>
+
+<histogram name="Memory.PurgeAndSuspend.V8MainThreadIsolateKB" units="KB">
+  <owner>tasak@google.com</owner>
+  <summary>
+    Blink's main thread isoalte heap usage when purging and suspending a
+    backgrounded renderer. Note: this metrics is for A/B testing.
+  </summary>
+</histogram>
+
 <histogram name="Memory.Renderer" units="KB">
   <owner>hajimehoshi@chromium.org</owner>
   <owner>kenjibaheux@google.com</owner>