INPUT element: stepDown() should not try to set an out-of-bound value.

third_party/WebKit/Source/core/html/HTMLInputElementTest.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/html/HTMLInputElement.h"
 
 #include "core/dom/Document.h"
 #include "core/frame/FrameHost.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/VisualViewport.h"
@@ skipping 144 matching lines @@
   document().view()->updateAllLifecyclePhases();
   HTMLInputElement* input = toHTMLInputElement(document().body()->firstChild());
 
   DateTimeChooserParameters params;
   bool success = input->setupDateTimeChooserParameters(params);
   EXPECT_TRUE(success);
   EXPECT_EQ("date", params.type);
   EXPECT_EQ(IntRect(16, 16, 400, 100), params.anchorRectInScreen);
 }
 
+TEST_F(HTMLInputElementTest, StepDownOverflow) {
+  HTMLInputElement* input = HTMLInputElement::create(document(), false);
+  input->setAttribute(HTMLNames::typeAttr, "date");
+  input->setAttribute(HTMLNames::minAttr, "2010-02-10");
+  input->setAttribute(HTMLNames::stepAttr, "9223372036854775556");
+  // InputType::applyStep() should not pass an out-of-range value to
+  // setValueAsDecimal, and WTF::msToYear() should not cause a DCHECK failure.
+  input->stepDown(1, ASSERT_NO_EXCEPTION);
+}
+
 }  // namespace blink