Added Dartium changes onto 45.0.2454.104

Source/platform/MIMETypeRegistry.cpp

Index: Source/platform/MIMETypeRegistry.cpp
diff --git a/Source/platform/MIMETypeRegistry.cpp b/Source/platform/MIMETypeRegistry.cpp
index 8887aeddc4f47e91c5b8a8d0af1e715051aa0f8c..4e33a83f33b7c09d6b395b454d054b6eba106de8 100644
--- a/Source/platform/MIMETypeRegistry.cpp
+++ b/Source/platform/MIMETypeRegistry.cpp
@@ -98,6 +98,12 @@ bool MIMETypeRegistry::isSupportedJavaScriptMIMEType(const String& mimeType)
         != WebMimeRegistry::IsNotSupported;
 }
 
+bool MIMETypeRegistry::isSupportedDartMIMEType(const String& mimeType)
+{
+    return blink::Platform::current()->mimeRegistry()->supportsDartMIMEType(mimeType)
+        != blink::WebMimeRegistry::IsNotSupported;
+}
+
 bool MIMETypeRegistry::isSupportedNonImageMIMEType(const String& mimeType)
 {
     return Platform::current()->mimeRegistry()->supportsNonImageMIMEType(mimeType.lower())