Add UMA for testing whether device supports memory mapping APK files with executable permissions.

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 aeeadc40ccdc87c7ca6faed92be7e5584057be9c..147eff8279f56d21b8db272c81002ec0ae7391db 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -2707,6 +2707,16 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   <summary>Is low memory device.</summary>
 </histogram>
 
+<histogram name="ChromiumAndroidLinker.LibraryLoadFromApkSupported"
+    enum="BooleanSupported">
+  <owner>petrcermak@chromium.org</owner>
+  <summary>
+    Whether the device supports loading a library directly from the APK file.
+    The functionality is checked and reported during every Chromium browser
+    process start up.
+  </summary>
+</histogram>
+
 <histogram name="ChromiumAndroidLinker.LoadedAtFixedAddressFailed"
     enum="Boolean">
   <obsolete>
@@ -39626,6 +39636,11 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   <int value="1" label="Success"/>
 </enum>
 
+<enum name="BooleanSupported" type="int">
+  <int value="0" label="Not supported"/>
+  <int value="1" label="Supported"/>
+</enum>
+
 <enum name="BooleanSuppressed" type="int">
   <int value="0" label="No suppressions"/>
   <int value="1" label="Suppressed"/>