File constructor understands lastModified.

LayoutTests/fast/files/file-constructor.html

Index: LayoutTests/fast/files/file-constructor.html
diff --git a/LayoutTests/fast/files/file-constructor.html b/LayoutTests/fast/files/file-constructor.html
index f615864f75e496d559deab8828f0874b669cf0b7..5e1af2391b9f960a7708883da8c6460c8586fba9 100644
--- a/LayoutTests/fast/files/file-constructor.html
+++ b/LayoutTests/fast/files/file-constructor.html
@@ -69,6 +69,8 @@ shouldThrow("new File([], 'world.html', {endings:'illegalValue'})", "'TypeError:
 shouldThrow("new File([], 'world.html', {endings:throwingObj})", "'Error'");
 shouldThrow("new File([], 'world.html', {type:throwingObj})", "'Error'");
 shouldThrow("new File([], 'world.html', {type:'hello\u00EE'})", "'SyntaxError: Failed to construct \\'File\\': The \"type\" property must consist of ASCII characters.'");
+shouldThrow("new File([], 'world.html', {lastModifiedDate: 'not a date'})", "'SyntaxError: Failed to construct \\'File\\': The \"lastModifiedDate\" property must be a Date instance.'");
+shouldThrow("new File([], 'world.html', {lastModifiedDate: null})", "'SyntaxError: Failed to construct \\'File\\': The \"lastModifiedDate\" property must be a Date instance.'");
 
 // Test various non-object literals being used as property bags.
 shouldThrow("(new File([], 'world.html', null)) instanceof window.File", "'TypeError: Failed to construct \\'File\\': The 3rd argument is not of type Object.'");
@@ -87,6 +89,14 @@ shouldBe("(new File([], 'world.html', {type:'text/html'})).type", "'text/html'")
 shouldBe("(new File([], 'world.html', {type:'text/html'})).size", "0");
 shouldBe("(new File([], 'world.html', {type:'text/plain;charset=UTF-8'})).type", "'text/plain;charset=utf-8'");
 
+// Test that the lastModificationDate is correctly added to the File.
+var aDate = new Date(441532800000);
+shouldBeTrue("(new File([], 'world.html', {lastModifiedDate: aDate})).lastModifiedDate instanceof Date");
+shouldBe("(new File([], 'world.html', {lastModifiedDate: aDate})).lastModifiedDate.valueOf()", "aDate.valueOf()");
+shouldBeTrue("(new File([], 'world.html', {lastModifiedDate: 441532800000})).lastModifiedDate instanceof Date");
+shouldBe("(new File([], 'world.html', {lastModifiedDate: 441532800000})).lastModifiedDate.valueOf()", "aDate.valueOf()");
+shouldBeTrue("Math.abs(Date.now() - (new File([], 'world.html')).lastModifiedDate) <= 1000");  // Unless specified, lastModifiedDate should default to now.
+
 // Test the number of expected arguments in the File constructor.
 shouldBe("window.File.length", "2");