memory coordinator: Add metrics for Android's onTrimMemory()

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 8ad8ca5d2a7ee7bfe3d6083e7a9126417e923f17..0154b793fce3b1f3d09a7bd5442cd9aa07157200 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -25563,6 +25563,30 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Memory.Coordinator.TrimMemoryLevel.Normal"
+    enum="TrimMemoryLevel">
+  <owner>bashi@chromium.org</owner>
+  <summary>
+    Android: Records trim memory level when the global state is NORMAL.
+  </summary>
+</histogram>
+
+<histogram name="Memory.Coordinator.TrimMemoryLevel.Suspended"
+    enum="TrimMemoryLevel">
+  <owner>bashi@chromium.org</owner>
+  <summary>
+    Android: Records trim memory level when the global state is SUSPENDED.
+  </summary>
+</histogram>
+
+<histogram name="Memory.Coordinator.TrimMemoryLevel.Throttled"
+    enum="TrimMemoryLevel">
+  <owner>bashi@chromium.org</owner>
+  <summary>
+    Android: Records trim memory level when the global state is THROTTLED.
+  </summary>
+</histogram>
+
 <histogram name="Memory.DiscardableAllocationSize" units="KB">
   <owner>reveman@chromium.org</owner>
   <summary>
@@ -102571,6 +102595,18 @@ value.
   <int value="2" label="unexpected other schemes"/>
 </enum>
 
+<enum name="TrimMemoryLevel" type="int">
+  <summary>
+    The level provided by Android's ComponentCallbacks2.onTrimMemory().
+  </summary>
+  <int value="5" label="TRIM_MEMORY_RUNNING_MODERATE"/>
+  <int value="10" label="TRIM_MEMORY_RUNNING_LOW"/>
+  <int value="15" label="TRIM_MEMORY_RUNNING_CRITICAL"/>
+  <int value="40" label="TRIM_MEMORY_BACKGROUND"/>
+  <int value="60" label="TRIM_MEMORY_MODERATE"/>
+  <int value="80" label="TRIM_MEMORY_COMPLETE"/>
+</enum>
+
 <enum name="UIEventType" type="int">
   <int value="0" label="Unknown"/>
   <int value="1" label="Touch released"/>