Add renderer memory metrics

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 c0b7cf8499249f533dcf3cbd702ffa1c809c4b82..40910b82cf8c1b6b328f45c34102fe54484ad74e 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -26698,6 +26698,62 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Memory.Experimental.Renderer.BlinkGCMB" units="MB">

[Ilya Sherman, 2017/01/12 01:04:14]

Optional nit: Are you sure that you want "MB" to be included in the metric name?
 It's already present in the units attribute, and IMO it makes the metric name
harder to read.

[keishi, 2017/01/12 01:58:00]

Done. Removed MB from names.

[keishi, 2017/01/12 01:58:00]

Done. Removed MB from the names.

+  <owner>keishi@chromium.org</owner>
+  <summary>
+    The memory usage of the BlinkGC allocator after a page load.
+  </summary>
+</histogram>

[Ilya Sherman, 2017/01/12 01:04:14]

To clarify, I'd suggest using histogram suffixes roughly like so:

<histogram name="Memory.Experimental.Renderer" base="true" units="MB">
  <owner>keishi@chromium.org</owner>
  <summary>
    The renderer process's memory usage after a page load.
  </summary>
</histogram>

<histogram_suffixes name="RendererMemoryAllocator" separator=".">
  <suffix name="BlinkGCMB" label="Constrained to the BlinkGC allocator">
  ...
  <suffix name="TotalAllocatedMB"
          label="Summed over the PartitionAlloc, malloc, discardable memory,
mainThreadIsolate() and BlinkGC allocators">
  ...
  <affected-histogram name="Memory.Experimental.Renderer">
</histogram_suffixes>

(as well as the histogram_suffixes element that you already have)

[keishi, 2017/01/12 01:58:00]

Done.

+
+<histogram name="Memory.Experimental.Renderer.DiscardableMB" units="MB">
+  <owner>keishi@chromium.org</owner>
+  <summary>
+    The memory usage of the discardable memory after a page load.
+  </summary>
+</histogram>
+
+<histogram name="Memory.Experimental.Renderer.MallocMB" units="MB">
+  <owner>keishi@chromium.org</owner>
+  <summary>The memory usage of the malloc after a page load.</summary>
+</histogram>
+
+<histogram name="Memory.Experimental.Renderer.NonDiscardableTotalAllocatedMB"
+    units="MB">
+  <owner>keishi@chromium.org</owner>
+  <summary>
+    The sum of the memory usages of PartitionAlloc, malloc, mainThreadIsolate()
+    and BlinkGC allocator after a page load.
+  </summary>
+</histogram>
+
+<histogram name="Memory.Experimental.Renderer.PartitionAllocMB" units="MB">
+  <owner>keishi@chromium.org</owner>
+  <summary>The memory usage of PartitionAlloc after a page load.</summary>
+</histogram>
+
+<histogram name="Memory.Experimental.Renderer.TotalAllocatedMB" units="MB">
+  <owner>keishi@chromium.org</owner>
+  <summary>
+    The sum of the memory usages of PartitionAlloc, malloc, discardable memory,
+    mainThreadIsolate() and BlinkGC allocator after a page load.
+  </summary>
+</histogram>
+
+<histogram name="Memory.Experimental.Renderer.TotalAllocatedPerRenderViewMB"
+    units="MB">
+  <owner>keishi@chromium.org</owner>
+  <summary>
+    The sum of the memory usages of PartitionAlloc, malloc, discardable memory,
+    mainThreadIsolate() and BlinkGC allocator divided by the number of
+    RenderViews after a page load.
+  </summary>
+</histogram>
+
+<histogram name="Memory.Experimental.Renderer.V8MainThreadIsolateMB" units="MB">
+  <owner>keishi@chromium.org</owner>
+  <summary>The memory usage of mainThreadIsolate() after a page load.</summary>
+</histogram>
+
 <histogram name="Memory.Extension" units="KB">
   <owner>hajimehoshi@chromium.org</owner>
   <owner>kenjibaheux@google.com</owner>
@@ -115044,6 +115100,22 @@ value.
   <affected-histogram name="Event.Latency.RendererImpl"/>
 </histogram_suffixes>
 
+<histogram_suffixes name="RendererMemoryTiming">
+  <affected-histogram name="Memory.Experimental.Renderer.BlinkGCMB"/>
+  <affected-histogram name="Memory.Experimental.Renderer.DiscardableMB"/>
+  <affected-histogram name="Memory.Experimental.Renderer.MallocMB"/>
+  <affected-histogram
+      name="Memory.Experimental.Renderer.NonDiscardableTotalAllocatedMB"/>
+  <suffix name="DidFinishLoad" label="DidFinishLoad"/>

[Ilya Sherman, 2017/01/12 01:04:14]

nit: I *think* this suffix is recorded every time a frame on the page reaches
DidFinishLoad().  Is that correct?  If so, please clarify this in the label. 
Also, I suspect that this might be confusing to interpret -- if a page has 4
frames, it will emit to this metric 4 times.  That will bias this metric towards
pages with more frames.  Is that desirable?

[keishi, 2017/01/12 01:58:00]

Done. Main frame only will be more stable but iframes like ads may be large
memory consumers so I want to have that data too.

+  <suffix name="MainFrameDidFinishLoad" label="Main frame DidFinishLoad"/>

[Ilya Sherman, 2017/01/12 01:04:14]

nit: Please move these suffixes above all of the affected-histogram entries.

[keishi, 2017/01/12 01:58:00]

Done.

+  <affected-histogram name="Memory.Experimental.Renderer.PartitionAllocMB"/>
+  <affected-histogram name="Memory.Experimental.Renderer.TotalAllocatedMB"/>
+  <affected-histogram
+      name="Memory.Experimental.Renderer.TotalAllocatedPerRenderViewMB"/>
+  <affected-histogram
+      name="Memory.Experimental.Renderer.V8MainThreadIsolateMB"/>
+</histogram_suffixes>
+
 <histogram_suffixes name="RequestMediaKeySystemAccessKeySystems" separator=".">
   <suffix name="ClearKey" label="Requests for the Clear Key key system."/>
   <suffix name="Unknown"