Replace WTF::emptyString{16Bit}() with a static global

third_party/WebKit/Source/core/html/forms/InputType.cpp

Index: third_party/WebKit/Source/core/html/forms/InputType.cpp
diff --git a/third_party/WebKit/Source/core/html/forms/InputType.cpp b/third_party/WebKit/Source/core/html/forms/InputType.cpp
index d336e716fb6519868e9638d2509d66134fae1c7e..1e6830e758e9efdf577a0c508cca48b10aa44c83 100644
--- a/third_party/WebKit/Source/core/html/forms/InputType.cpp
+++ b/third_party/WebKit/Source/core/html/forms/InputType.cpp
@@ -337,13 +337,13 @@ std::pair<String, String> InputType::validationMessage(
   // The order of the following checks is meaningful. e.g. We'd like to show the
   // badInput message even if the control has other validation errors.
   if (inputTypeView.hasBadInput())
-    return std::make_pair(badInputText(), emptyString());
+    return std::make_pair(badInputText(), emptyString);
 
   if (valueMissing(value))
-    return std::make_pair(valueMissingText(), emptyString());
+    return std::make_pair(valueMissingText(), emptyString);
 
   if (typeMismatch())
-    return std::make_pair(typeMismatchText(), emptyString());
+    return std::make_pair(typeMismatchText(), emptyString);
 
   if (patternMismatch(value)) {
     // https://html.spec.whatwg.org/multipage/forms.html#attr-input-pattern
@@ -356,32 +356,32 @@ std::pair<String, String> InputType::validationMessage(
         element().fastGetAttribute(titleAttr).getString());
   }
 
-  if (element().tooLong())
+  if (element().tooLong()) {
     return std::make_pair(locale().validationMessageTooLongText(
                               value.length(), element().maxLength()),
-                          emptyString());
+                          emptyString);
+  }
 
-  if (element().tooShort())
+  if (element().tooShort()) {
     return std::make_pair(locale().validationMessageTooShortText(
                               value.length(), element().minLength()),
-                          emptyString());
+                          emptyString);
+  }
 
   if (!isSteppable())
-    return std::make_pair(emptyString(), emptyString());
+    return std::make_pair(emptyString, emptyString);
 
   const Decimal numericValue = parseToNumberOrNaN(value);
   if (!numericValue.isFinite())
-    return std::make_pair(emptyString(), emptyString());
+    return std::make_pair(emptyString, emptyString);
 
   StepRange stepRange(createStepRange(RejectAny));
 
   if (numericValue < stepRange.minimum())
-    return std::make_pair(rangeUnderflowText(stepRange.minimum()),
-                          emptyString());
+    return std::make_pair(rangeUnderflowText(stepRange.minimum()), emptyString);
 
   if (numericValue > stepRange.maximum())
-    return std::make_pair(rangeOverflowText(stepRange.maximum()),
-                          emptyString());
+    return std::make_pair(rangeOverflowText(stepRange.maximum()), emptyString);
 
   if (stepRange.stepMismatch(numericValue)) {
     DCHECK(stepRange.hasStep());
@@ -391,25 +391,27 @@ std::pair<String, String> InputType::validationMessage(
                              ? candidate1 + stepRange.step()
                              : candidate1 - stepRange.step();
     if (!candidate2.isFinite() || candidate2 < stepRange.minimum() ||
-        candidate2 > stepRange.maximum())
+        candidate2 > stepRange.maximum()) {
       return std::make_pair(
           locale().queryString(
               WebLocalizedString::ValidationStepMismatchCloseToLimit,
               localizedCandidate1),
-          emptyString());
+          emptyString);
+    }
     String localizedCandidate2 = localizeValue(serialize(candidate2));
-    if (candidate1 < candidate2)
+    if (candidate1 < candidate2) {
       return std::make_pair(
           locale().queryString(WebLocalizedString::ValidationStepMismatch,
                                localizedCandidate1, localizedCandidate2),
-          emptyString());
+          emptyString);
+    }
     return std::make_pair(
         locale().queryString(WebLocalizedString::ValidationStepMismatch,
                              localizedCandidate2, localizedCandidate1),
-        emptyString());
+        emptyString);
   }
 
-  return std::make_pair(emptyString(), emptyString());
+  return std::make_pair(emptyString, emptyString);
 }
 
 Decimal InputType::parseToNumber(const String&,