ART: Remove unused JobjectComparator.

Unused since
    https://android-review.googlesource.com/144043 .

Test: Rely on TreeHugger.
Change-Id: I0cf004e66ba2698bb3dc45804d71f9d5ee3647fd
diff --git a/runtime/Android.bp b/runtime/Android.bp
index 05e9239..116453b 100644
--- a/runtime/Android.bp
+++ b/runtime/Android.bp
@@ -115,7 +115,6 @@
         "jni/java_vm_ext.cc",
         "jni/jni_env_ext.cc",
         "jni/jni_internal.cc",
-        "jobject_comparator.cc",
         "linear_alloc.cc",
         "managed_stack.cc",
         "method_handles.cc",
diff --git a/runtime/jobject_comparator.cc b/runtime/jobject_comparator.cc
deleted file mode 100644
index 4c45e38..0000000
--- a/runtime/jobject_comparator.cc
+++ /dev/null
@@ -1,56 +0,0 @@
-/*
- * Copyright (C) 2012 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include "jobject_comparator.h"
-
-#include "mirror/array-inl.h"
-#include "mirror/class-inl.h"
-#include "mirror/object-inl.h"
-#include "scoped_thread_state_change-inl.h"
-
-namespace art {
-
-bool JobjectComparator::operator()(jobject jobj1, jobject jobj2) const {
-  // Ensure null references and cleared jweaks appear at the end.
-  if (jobj1 == nullptr) {
-    return true;
-  } else if (jobj2 == nullptr) {
-    return false;
-  }
-  ScopedObjectAccess soa(Thread::Current());
-  StackHandleScope<2> hs(soa.Self());
-  Handle<mirror::Object> obj1(hs.NewHandle(soa.Decode<mirror::Object>(jobj1)));
-  Handle<mirror::Object> obj2(hs.NewHandle(soa.Decode<mirror::Object>(jobj2)));
-  if (obj1 == nullptr) {
-    return true;
-  } else if (obj2 == nullptr) {
-    return false;
-  }
-  // Sort by class...
-  if (obj1->GetClass() != obj2->GetClass()) {
-    return obj1->GetClass()->IdentityHashCode() < obj2->GetClass()->IdentityHashCode();
-  }
-  // ...then by size...
-  const size_t count1 = obj1->SizeOf();
-  const size_t count2 = obj2->SizeOf();
-  if (count1 != count2) {
-    return count1 < count2;
-  }
-  // ...and finally by identity hash code.
-  return obj1->IdentityHashCode() < obj2->IdentityHashCode();
-}
-
-}  // namespace art
diff --git a/runtime/jobject_comparator.h b/runtime/jobject_comparator.h
deleted file mode 100644
index 698d667..0000000
--- a/runtime/jobject_comparator.h
+++ /dev/null
@@ -1,30 +0,0 @@
-/*
- * Copyright (C) 2012 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#ifndef ART_RUNTIME_JOBJECT_COMPARATOR_H_
-#define ART_RUNTIME_JOBJECT_COMPARATOR_H_
-
-#include <jni.h>
-
-namespace art {
-
-struct JobjectComparator {
-  bool operator()(jobject jobj1, jobject jobj2) const;
-};
-
-}  // namespace art
-
-#endif  // ART_RUNTIME_JOBJECT_COMPARATOR_H_