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

base/android/linker/linker_jni.cc

Index: base/android/linker/linker_jni.cc
diff --git a/base/android/linker/linker_jni.cc b/base/android/linker/linker_jni.cc
index 79dd20103e7add06b2b30dd0550193682cbb7d50..e330a27f29ba7cfd2a60ddb60e7761a830855e54 100644
--- a/base/android/linker/linker_jni.cc
+++ b/base/android/linker/linker_jni.cc
@@ -574,6 +574,19 @@ jlong GetRandomBaseLoadAddress(JNIEnv* env, jclass clazz, jlong bytes) {
   return static_cast<jlong>(reinterpret_cast<uintptr_t>(address));
 }
 
+// Test whether the device supports memory mapping APK files with executable
+// permissions.
+//
+// |env| is the current JNI environment handle and is ignored here.
+// |clazz| is the static class handle for org.chromium.base.Linker,
+// and is ignored here.
+// |apkfile_name| is the filename of the APK.
+// Returns true if supported.
+jboolean TestLoadFromApk(JNIEnv* env, jclass clazz, jstring apkfile_name) {
+  String apkfile_name_str(env, apkfile_name);
+  return crazy_linker_test_load_from_apk(apkfile_name_str.c_str());
+}
+
 const JNINativeMethod kNativeMethods[] = {
     {"nativeLoadLibrary",
      "("
@@ -623,7 +636,13 @@ const JNINativeMethod kNativeMethods[] = {
      "J"
      ")"
      "J",
-     reinterpret_cast<void*>(&GetRandomBaseLoadAddress)}, };
+     reinterpret_cast<void*>(&GetRandomBaseLoadAddress)},
+     {"nativeTestLoadFromApk",
+      "("
+      "Ljava/lang/String;"
+      ")"
+      "Z",
+      reinterpret_cast<void*>(&TestLoadFromApk)}, };
 
 }  // namespace