Mute common case DexFile.isDexOptNeeded log spam

Bug: 18914409
Change-Id: I885f1aa87c48ff25353d44b720c7cff24ed01e45
diff --git a/runtime/native/dalvik_system_DexFile.cc b/runtime/native/dalvik_system_DexFile.cc
index f37312e..44c6d87 100644
--- a/runtime/native/dalvik_system_DexFile.cc
+++ b/runtime/native/dalvik_system_DexFile.cc
@@ -301,7 +301,10 @@
                                                         nullptr,
                                                         false, &error_msg));
   if (oat_file.get() == nullptr) {
-    if (kReasonLogging) {
+    // Note that even though this is kDexoptNeeded, we use
+    // kVerboseLogging instead of the usual kReasonLogging since it is
+    // the common case on first boot and very spammy.
+    if (kVerboseLogging) {
       LOG(INFO) << "DexFile_isDexOptNeeded failed to open oat file '" << oat_filename
           << "' for file location '" << filename << "': " << error_msg;
     }