Make console.memory writeable

Source/core/timing/ConsoleMemory.idl

Index: Source/core/timing/ConsoleMemory.idl
diff --git a/Source/core/timing/ConsoleMemory.idl b/Source/core/timing/ConsoleMemory.idl
index bdd31e20383d592a38ab1140ee9328a59fd7dbd2..7aa4952a4b224e0a68e9553060907557f3f0cff8 100644
--- a/Source/core/timing/ConsoleMemory.idl
+++ b/Source/core/timing/ConsoleMemory.idl
@@ -5,5 +5,6 @@
 [
     ImplementedAs=ConsoleMemory,
 ] partial interface Console {
-    readonly attribute MemoryInfo memory;
+    // We can't make the attribute readonly as it breaks existing code that relies on being able to assign to console.memory in strict mode. Instead, the setter just ignores the passed value.  http://crbug.com/468611
+    attribute MemoryInfo memory;
 };