Picture element initial implementation

Source/core/html/parser/HTMLResourcePreloader.cpp

Index: Source/core/html/parser/HTMLResourcePreloader.cpp
diff --git a/Source/core/html/parser/HTMLResourcePreloader.cpp b/Source/core/html/parser/HTMLResourcePreloader.cpp
index 22ebf212b6e39d4abb77a4b21d6da6566ca707b6..64f90829ee4bf46899af7507fdca979e16c9fba8 100644
--- a/Source/core/html/parser/HTMLResourcePreloader.cpp
+++ b/Source/core/html/parser/HTMLResourcePreloader.cpp
@@ -79,12 +79,26 @@ static bool mediaAttributeMatches(Frame* frame, RenderStyle* renderStyle, const
 
 void HTMLResourcePreloader::preload(PassOwnPtr<PreloadRequest> preload)
 {
+    if (preload->bundleStart()) {
+        m_inBundle = true;
+        return;
+    }
+    if (preload->bundleEnd()) {
+        m_inBundle = false;
+        m_foundBundleResource = false;
+        return;
+    }
     ASSERT(m_document->frame());
     ASSERT(m_document->renderer());
     ASSERT(m_document->renderer()->style());
     if (!preload->media().isEmpty() && !mediaAttributeMatches(m_document->frame(), m_document->renderer()->style(), preload->media()))
         return;
 
+    if (m_inBundle && m_foundBundleResource)
+        return;
+
+    m_foundBundleResource = true;
+
     CachedResourceRequest request = preload->resourceRequest(m_document);
     m_document->cachedResourceLoader()->preload(preload->resourceType(), request, preload->charset());
 }