Remove extraneous SubtreeStyleChange for min/maxlength changes.

Validation already takes care of :valid/:invalid changes through
invalidation sets. This reduces the number of elements being recalculated
and gets rid of a SubtreeStyleChange which relies on sibling tree recalcs.

R=tkent@chromium.org
BUG=557440

Review URL: https://codereview.chromium.org/1458363003

Cr-Commit-Position: refs/heads/master@{#361123}

third_party/WebKit/LayoutTests/fast/css/invalidation/valid-invalid-pseudo-expected.txt

@@ -15,6 +15,12 @@ PASS getComputedStyle(formValid, '').backgroundColor is green
 PASS getComputedStyle(formInvalid, '').backgroundColor is transparent
 PASS internals.updateStyleAndReturnAffectedElementCount() is 2
 PASS getComputedStyle(formInvalid, '').backgroundColor is green
+PASS getComputedStyle(maxlengthInvalid, '').backgroundColor is transparent
+PASS internals.updateStyleAndReturnAffectedElementCount() is 1
+PASS getComputedStyle(maxlengthInvalid, '').backgroundColor is green
+PASS getComputedStyle(minlengthInvalid, '').backgroundColor is transparent
+PASS internals.updateStyleAndReturnAffectedElementCount() is 1
+PASS getComputedStyle(minlengthInvalid, '').backgroundColor is green
 PASS successfullyParsed is true
 
 TEST COMPLETE
@@ -23,3 +29,5 @@ TEST COMPLETE
     
     
 
+
+

third_party/WebKit/LayoutTests/fast/css/invalidation/valid-invalid-pseudo.html

@@ -5,7 +5,9 @@ input { background-color: transparent }
 #inputValid:valid,
 #inputInvalid:invalid,
 #formValid:valid,
-#formInvalid:invalid {
+#formInvalid:invalid,
+#maxlengthInvalid:invalid,
+#minlengthInvalid:invalid {
     background-color: green
 }
 
@@ -42,6 +44,16 @@ input + div {
     <div></div>
     <div></div>
 </div>
+<input id="maxlengthInvalid" type="text"></input>
+<div>
+    <div></div>
+    <div></div>
+</div>
+<input id="minlengthInvalid" type="text"></input>
+<div>
+    <div></div>
+    <div></div>
+</div>
 
 <script>
 description("Use descendant invalidation sets for :valid and :invalid pseudo classes.")
@@ -77,4 +89,27 @@ if (window.internals)
     shouldBe("internals.updateStyleAndReturnAffectedElementCount()", "2");
 shouldBe("getComputedStyle(formInvalid, '').backgroundColor", "green");
 
+// Make sure the value is user input, otherwise setting maxlength/minlength
+// won't cause a validation.
+if (window.eventSender) {
+    maxlengthInvalid.focus();
+    eventSender.keyDown("x");
+    eventSender.keyDown("x");
+    minlengthInvalid.focus();
+    eventSender.keyDown("x");
+}
+
+shouldBe("getComputedStyle(maxlengthInvalid, '').backgroundColor", "transparent");
+document.body.offsetTop; // Force recalc.
+maxlengthInvalid.setAttribute("maxlength", "1");
+if (window.internals)
+    shouldBe("internals.updateStyleAndReturnAffectedElementCount()", "1");
+shouldBe("getComputedStyle(maxlengthInvalid, '').backgroundColor", "green");
+
+shouldBe("getComputedStyle(minlengthInvalid, '').backgroundColor", "transparent");
+document.body.offsetTop; // Force recalc.
+minlengthInvalid.setAttribute("minlength", "2");
+if (window.internals)
+    shouldBe("internals.updateStyleAndReturnAffectedElementCount()", "1");
+shouldBe("getComputedStyle(minlengthInvalid, '').backgroundColor", "green");
 </script>

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

@@ -1703,7 +1703,6 @@ void HTMLInputElement::parseMaxLengthAttribute(const AtomicString& value)
     m_maxLength = maxLength;
     if (oldMaxLength != maxLength)
         updateValueIfNeeded();
-    setNeedsStyleRecalc(SubtreeStyleChange, StyleChangeReasonForTracing::fromAttribute(maxlengthAttr));
     setNeedsValidityCheck();
 }
 
@@ -1715,7 +1714,6 @@ void HTMLInputElement::parseMinLengthAttribute(const AtomicString& value)
     if (minLength < 0)
         minLength = 0;
     m_minLength = minLength;
-    setNeedsStyleRecalc(SubtreeStyleChange, StyleChangeReasonForTracing::fromAttribute(minlengthAttr));
     setNeedsValidityCheck();
 }