Updating <object> upon changing "data", "classid", "type" attributes.

Source/core/html/HTMLObjectElement.cpp

Index: Source/core/html/HTMLObjectElement.cpp
diff --git a/Source/core/html/HTMLObjectElement.cpp b/Source/core/html/HTMLObjectElement.cpp
index 76d2709da0c1a3b12500a1c79257659dad30e836..51ec27e27a930e7e152f6e831cc0925fd9092400 100644
--- a/Source/core/html/HTMLObjectElement.cpp
+++ b/Source/core/html/HTMLObjectElement.cpp
@@ -98,22 +98,25 @@ void HTMLObjectElement::parseAttribute(const QualifiedName& name, const AtomicSt
         size_t pos = m_serviceType.find(";");
         if (pos != kNotFound)
             m_serviceType = m_serviceType.left(pos);
-        if (renderer())
-            setNeedsWidgetUpdate(true);
+        setNeedsWidgetUpdate(true);
+        // Per spec, only re-determine representation iff 'classid' and 'data' aren't present.
+        if (!fastHasAttribute(classidAttr) && !fastHasAttribute(dataAttr))
+            setNeedsStyleRecalc();
     } else if (name == dataAttr) {
         m_url = stripLeadingAndTrailingHTMLSpaces(value);
-        if (renderer()) {
-            setNeedsWidgetUpdate(true);
-            if (isImageType()) {
-                if (!m_imageLoader)
-                    m_imageLoader = adoptPtr(new HTMLImageLoader(this));
-                m_imageLoader->updateFromElementIgnoringPreviousError();
-            }
+        setNeedsWidgetUpdate(true);
+        if (renderer() && isImageType()) {
+            if (!m_imageLoader)
+                m_imageLoader = adoptPtr(new HTMLImageLoader(this));

[eseidel, 2014/01/15 18:40:09]

Lame that the original author didn't just add an ensureImageLoader() function.
:)

+            m_imageLoader->updateFromElementIgnoringPreviousError();
+        } else if (!fastHasAttribute(classidAttr)) {

[eseidel, 2014/01/15 18:40:09]

I don't understand this bit?  Maybe we should abstract the "!classid && !data
into a helper function which has a nice name?  shouldReloadPluginOnAttrChange()

[sof, 2014/01/15 19:52:54]

That's a good suggestion; now done (taking care not to accidentally upset the
handling of images.)

+            setNeedsStyleRecalc();
         }
     } else if (name == classidAttr) {
         m_classId = value;
-        if (renderer())
-            setNeedsWidgetUpdate(true);
+        setNeedsWidgetUpdate(true);
+        // Always re-determine representation upon 'classid' changing.
+        setNeedsStyleRecalc();
     } else if (name == onbeforeloadAttr) {
         setAttributeEventListener(EventTypeNames::beforeload, createAttributeEventListener(this, name, value));
     } else {