Make custom element name checks faster and fewer

third_party/WebKit/Source/core/dom/custom/CustomElement.h

Index: third_party/WebKit/Source/core/dom/custom/CustomElement.h
diff --git a/third_party/WebKit/Source/core/dom/custom/CustomElement.h b/third_party/WebKit/Source/core/dom/custom/CustomElement.h
index ec8f3c1546b5e74181b1b0e7f308088f848439f2..7974b2508b5d8191e1633172847b5c8e8dbdf0ab 100644
--- a/third_party/WebKit/Source/core/dom/custom/CustomElement.h
+++ b/third_party/WebKit/Source/core/dom/custom/CustomElement.h
@@ -8,6 +8,8 @@
 #include "core/CoreExport.h"
 #include "core/HTMLNames.h"
 #include "core/dom/Element.h"
+#include "platform/RuntimeEnabledFeatures.h"
+#include "platform/text/Character.h"
 #include "wtf/Allocator.h"
 #include "wtf/text/AtomicString.h"
 
@@ -32,14 +34,43 @@ public:
 
     static CustomElementDefinition* definitionForElement(const Element*);
 
-    static bool isValidName(const AtomicString& name);
+    static bool isValidName(const AtomicString& name)
+    {
+        if (!name.length() || name[0] < 'a' || name[0] > 'z')

[kouhei (in TOK), 2016/08/29 06:59:55]

Can we refactor the name[0] check as a platform/text/Character method?

+            return false;
+
+        bool hasHyphens = false;
+        if (name.is8Bit()) {
+            for (size_t i = 1; i < name.length(); ) {
+                UChar ch = name[i++];
+                if (ch == '-')
+                    hasHyphens = true;
+                else if (!Character::isPotentialCustomElementNameChar(ch))
+                    return false;
+            }
+        } else {
+            for (size_t i = 1; i < name.length(); ) {
+                UChar32 ch;
+                U16_NEXT(name.characters16(), i, name.length(), ch);
+                if (ch == '-')
+                    hasHyphens = true;
+                else if (!Character::isPotentialCustomElementNameChar(ch))
+                    return false;
+            }
+        }
+        return hasHyphens && !isHyphenContainingElementName(name);
+    }
+
+    static bool shouldCreateCustomElement(const AtomicString& localName)
+    {
+        return RuntimeEnabledFeatures::customElementsV1Enabled()
+            && isValidName(localName);
+    }
 
-    static bool shouldCreateCustomElement(const AtomicString& localName);
     static bool shouldCreateCustomElement(const QualifiedName&);
 
-    static HTMLElement* createCustomElementSync(Document&, const AtomicString& localName, ExceptionState&);
-    static HTMLElement* createCustomElementSync(Document&, const QualifiedName&, ExceptionState&);
-    static HTMLElement* createCustomElementSync(Document&, const QualifiedName&);
+    static HTMLElement* createCustomElementSync(Document&, const AtomicString& localName, ExceptionState*);

[esprehn, 2016/08/30 21:32:32]

We normally do ExceptionState& and then default argument = ASSERT_NO_EXCEPTION

+    static HTMLElement* createCustomElementSync(Document&, const QualifiedName&, ExceptionState*);
     static HTMLElement* createCustomElementAsync(Document&, const QualifiedName&);
 
     static HTMLElement* createFailedElement(Document&, const QualifiedName&);
@@ -55,6 +86,11 @@ public:
 
 private:
     static HTMLElement* createUndefinedElement(Document&, const QualifiedName&);
+
+    // A hyphen-containing element name is an element name from a
+    // specification which contains a hyphen, for example, font-face
+    // from SVG. These are not allowed as custom element names.
+    static bool isHyphenContainingElementName(const AtomicString&);
 };
 
 } // namespace blink