Add native log and uma stat when all input shared memory buffers are full

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 f1a7757d876c3211599410035ca16d9cd43ba0f6..ec139df8a262e6f5d893287f0a5d694311d46edf 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -10971,7 +10971,7 @@ Therefore, the affected-histogram name has to have at least one dot in it.
 
 <histogram name="Media.AudioInputControllerCaptureStartupSuccess"
     enum="CaptureStartupResult">
-  <owner>dalecurtis@chromium.org</owner>
+  <owner>xians@chromium.org</owner>
   <summary>
     Whether capture started successfully after an input stream startup was
     requested.
@@ -10989,6 +10989,14 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   <summary>Measures the time taken for AudioInputDeviceManager::</summary>
 </histogram>
 
+<histogram name="Media.AudioInputSyncWriterBuffersAreFull"
+    enum="AudioInputBufferType">
+  <owner>xians@chromium.org</owner>
+  <summary>
+    Counters for AudioInputSyncWriter::Write() where all the buffers are full.

[Alexei Svitkine (slow), 2014/08/29 22:22:18]

Can the description be expanded to explain the enum values? (i.e. if all buffers
are full, how does the buffer type fit into it?)

[no longer working on chromium, 2014/09/02 10:00:21]

Done, PTAL.

+  </summary>
+</histogram>
+
 <histogram name="Media.AudioOutputController" units="ms">
   <owner>dalecurtis@chromium.org</owner>
   <summary>Measures the time taken for AudioOutputController::</summary>
@@ -37619,6 +37627,11 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   <int value="8" label="k1920"/>
 </enum>
 
+<enum name="AudioInputBufferType" type="int">
+  <int value="0" label="single buffer"/>
+  <int value="1" label="circular buffer"/>
+</enum>
+
 <enum name="AudioInputSilenceReport" type="int">
   <int value="0" label="No measurement"/>
   <int value="1" label="Only audio"/>