File constructor understands lastModified.

Source/bindings/v8/custom/V8BlobCustomHelpers.h

Index: Source/bindings/v8/custom/V8BlobCustomHelpers.h
diff --git a/Source/bindings/v8/custom/V8BlobCustomHelpers.h b/Source/bindings/v8/custom/V8BlobCustomHelpers.h
index 8bb22f0dac3b41646943a1244aba78b405b509df..1b29815aabf43cd5eeec7a1c83b2dab958a0a2c3 100644
--- a/Source/bindings/v8/custom/V8BlobCustomHelpers.h
+++ b/Source/bindings/v8/custom/V8BlobCustomHelpers.h
@@ -40,12 +40,32 @@ class BlobBuilder;
 // Shared code between the custom constructor bindings for Blob and File.
 namespace V8BlobCustomHelpers {
 
+// Parsed properties from a BlobPropertyBag or a FilePropertyBag.
+struct ParsedProperties {
+    String contentType;
+    String endings;
+
+    // False if this contains the properties of a BlobPropertyBag.
+    bool hasFileProperties;
+
+private:
+    double m_lastModifiedDate;
+    bool m_hasLastModifiedDate;
+
+
+public:
+    void setLastModifiedDate(double);
+    double lastModifiedDate();
+
+    ParsedProperties(bool hasFileProperties);
+};
+
 // Extracts the "type" and "endings" properties out of the BlobPropertyBag passed to a Blob constructor.
 // http://www.w3.org/TR/FileAPI/#constructorParams
 // Returns true if everything went well, false if a JS exception was thrown.
-bool processBlobPropertyBag(v8::Local<v8::Value> propertyBag, const char* blobClassName, String& contentType, String& endings, v8::Isolate*);
+bool processBlobPropertyBag(v8::Local<v8::Value> propertyBag, const char* blobClassName, ParsedProperties&, v8::Isolate*);
 
-// Appends the blobParts passed to a Blob constructor into a BlobBuilder.
+// Appends the blobParts passed to a Blob or File constructor into a BlobBuilder.
 // http://www.w3.org/TR/FileAPI/#constructorParams
 // Returns true if everything went well, false if a JS exception was thrown.
 bool processBlobParts(v8::Local<v8::Object> blobParts, uint32_t blobPartsLength, const String& endings, BlobBuilder&, v8::Isolate*);