Replace NULL with nullptr

Also fixed some lines that were too long, and a few other minor
details.

Change-Id: I6efba5fb6e03eb5d0a300fddb2a75bf8e2f175cb
diff --git a/runtime/mirror/dex_cache_test.cc b/runtime/mirror/dex_cache_test.cc
index 1d6846b..228fce5 100644
--- a/runtime/mirror/dex_cache_test.cc
+++ b/runtime/mirror/dex_cache_test.cc
@@ -34,10 +34,10 @@
 TEST_F(DexCacheTest, Open) {
   ScopedObjectAccess soa(Thread::Current());
   StackHandleScope<1> hs(soa.Self());
-  ASSERT_TRUE(java_lang_dex_file_ != NULL);
+  ASSERT_TRUE(java_lang_dex_file_ != nullptr);
   Handle<DexCache> dex_cache(
       hs.NewHandle(class_linker_->AllocDexCache(soa.Self(), *java_lang_dex_file_)));
-  ASSERT_TRUE(dex_cache.Get() != NULL);
+  ASSERT_TRUE(dex_cache.Get() != nullptr);
 
   EXPECT_EQ(java_lang_dex_file_->NumStringIds(), dex_cache->NumStrings());
   EXPECT_EQ(java_lang_dex_file_->NumTypeIds(),   dex_cache->NumResolvedTypes());