Literal AtomicString construction can rely on strlen optimization.

third_party/WebKit/Source/core/html/HTMLImageFallbackHelper.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/HTMLImageFallbackHelper.h"
 
 #include "core/HTMLNames.h"
 #include "core/InputTypeNames.h"
 #include "core/dom/ElementRareData.h"
 #include "core/dom/Text.h"
@@ skipping 18 matching lines @@
     bool noSrcsetSpecified = !element.hasAttribute(srcsetAttr) || element.getAttribute(srcsetAttr).isNull() || element.getAttribute(srcsetAttr).isEmpty();
     return noSrcSpecified && noSrcsetSpecified;
 }
 
 void HTMLImageFallbackHelper::createAltTextShadowTree(Element& element)
 {
     ShadowRoot& root = element.ensureUserAgentShadowRoot();
 
     RefPtrWillBeRawPtr<HTMLDivElement> container = HTMLDivElement::create(element.document());
     root.appendChild(container);
-    container->setAttribute(idAttr, AtomicString("alttext-container", AtomicString::ConstructFromLiteral));
+    container->setAttribute(idAttr, AtomicString("alttext-container"));
     container->setInlineStyleProperty(CSSPropertyOverflow, CSSValueHidden);
     container->setInlineStyleProperty(CSSPropertyBorderWidth, 1, CSSPrimitiveValue::UnitType::Pixels);
     container->setInlineStyleProperty(CSSPropertyBorderStyle, CSSValueSolid);
     container->setInlineStyleProperty(CSSPropertyBorderColor, CSSValueSilver);
     container->setInlineStyleProperty(CSSPropertyDisplay, CSSValueInlineBlock);
     container->setInlineStyleProperty(CSSPropertyBoxSizing, CSSValueBorderBox);
     container->setInlineStyleProperty(CSSPropertyPadding, 1, CSSPrimitiveValue::UnitType::Pixels);
 
     RefPtrWillBeRawPtr<HTMLImageElement> brokenImage = HTMLImageElement::create(element.document());
     container->appendChild(brokenImage);
     brokenImage->setIsFallbackImage();
-    brokenImage->setAttribute(idAttr, AtomicString("alttext-image", AtomicString::ConstructFromLiteral));
-    brokenImage->setAttribute(widthAttr, AtomicString("16", AtomicString::ConstructFromLiteral));
-    brokenImage->setAttribute(heightAttr, AtomicString("16", AtomicString::ConstructFromLiteral));
-    brokenImage->setAttribute(alignAttr, AtomicString("left", AtomicString::ConstructFromLiteral));
+    brokenImage->setAttribute(idAttr, AtomicString("alttext-image"));
+    brokenImage->setAttribute(widthAttr, AtomicString("16"));
+    brokenImage->setAttribute(heightAttr, AtomicString("16"));
+    brokenImage->setAttribute(alignAttr, AtomicString("left"));
     brokenImage->setInlineStyleProperty(CSSPropertyMargin, 0, CSSPrimitiveValue::UnitType::Pixels);
 
     RefPtrWillBeRawPtr<HTMLDivElement> altText = HTMLDivElement::create(element.document());
     container->appendChild(altText);
-    altText->setAttribute(idAttr, AtomicString("alttext", AtomicString::ConstructFromLiteral));
+    altText->setAttribute(idAttr, AtomicString("alttext"));
     altText->setInlineStyleProperty(CSSPropertyOverflow, CSSValueHidden);
     altText->setInlineStyleProperty(CSSPropertyDisplay, CSSValueBlock);
 
     RefPtrWillBeRawPtr<Text> text = Text::create(element.document(), toHTMLElement(element).altText());
     altText->appendChild(text);
 }
 
 PassRefPtr<ComputedStyle> HTMLImageFallbackHelper::customStyleForAltText(Element& element, PassRefPtr<ComputedStyle> newStyle)
 {
     // If we have an author shadow root or have not created the UA shadow root yet, bail early. We can't
@@ skipping 35 matching lines @@
     // This preserves legacy behaviour originally defined when alt-text was managed by LayoutImage.
     if (noImageSourceSpecified(element))
         brokenImage->setInlineStyleProperty(CSSPropertyDisplay, CSSValueNone);
     else
         brokenImage->setInlineStyleProperty(CSSPropertyDisplay, CSSValueInline);
 
     return newStyle;
 }
 
 } // namespace blink