Corrected assert for cacheable stylesheets.

third_party/WebKit/Source/core/css/CSSStyleSheet.cpp

Index: third_party/WebKit/Source/core/css/CSSStyleSheet.cpp
diff --git a/third_party/WebKit/Source/core/css/CSSStyleSheet.cpp b/third_party/WebKit/Source/core/css/CSSStyleSheet.cpp
index d715f78fbc66c0be0b8b01c01389ff72722d8af6..bd4773f8e3088ca945b3e988e3a68d266b40e041 100644
--- a/third_party/WebKit/Source/core/css/CSSStyleSheet.cpp
+++ b/third_party/WebKit/Source/core/css/CSSStyleSheet.cpp
@@ -135,6 +135,15 @@ CSSStyleSheet::~CSSStyleSheet()
 {
 }
 
+#if ENABLE(ASSERT)
+
+static bool isStyleElement(const Node* node)
+{
+    return node && (isHTMLStyleElement(node) || isSVGStyleElement(node));
+}
+
+#endif // ENABLE(ASSERT)
+
 void CSSStyleSheet::willMutateRules()
 {
     // If we are the only client it is safe to mutate.
@@ -146,7 +155,8 @@ void CSSStyleSheet::willMutateRules()
         return;
     }
     // Only cacheable stylesheets should have multiple clients.
-    ASSERT(m_contents->isCacheable());
+    ASSERT((isStyleElement(ownerNode()) && m_contents->isCacheableForStyleElement())
+        || m_contents->isCacheableForResource());
 
     // Copy-on-write.
     m_contents->unregisterClient(this);