Add support using EXPECT_EQ with NullableString16 objects.

base/strings/nullable_string16.h

Index: base/strings/nullable_string16.h
diff --git a/base/strings/nullable_string16.h b/base/strings/nullable_string16.h
index 73fe81e0842034eba4d918cafeb58dcd8d22f2a0..16dcfe23d38093195c91f9e5b549ebf23079d1e1 100644
--- a/base/strings/nullable_string16.h
+++ b/base/strings/nullable_string16.h
@@ -5,6 +5,9 @@
 #ifndef BASE_STRINGS_NULLABLE_STRING16_H_
 #define BASE_STRINGS_NULLABLE_STRING16_H_
 
+#include <iosfwd>
+
+#include "base/base_export.h"
 #include "base/strings/string16.h"
 
 namespace base {
@@ -14,7 +17,7 @@ namespace base {
 // empty is meaningful.
 class NullableString16 {
  public:
-  NullableString16() : is_null_(false) { }
+  NullableString16() : is_null_(true) { }
   explicit NullableString16(bool is_null) : is_null_(is_null) { }
   NullableString16(const string16& string, bool is_null)
       : string_(string), is_null_(is_null) {
@@ -28,6 +31,17 @@ class NullableString16 {
   bool is_null_;
 };
 
+inline bool operator==(const NullableString16& a, const NullableString16& b) {
+  return a.is_null() == b.is_null() && a.string() == b.string();
+}
+
+inline bool operator!=(const NullableString16& a, const NullableString16& b) {
+  return !(a == b);
+}
+
+BASE_EXPORT std::ostream& operator<<(std::ostream& out,
+                                     const NullableString16& value);
+
 }  // namespace
 
 // TODO(avi) update users of NullableString16 to use the namespace and remove