Remove meaningless uses of [TypeChecking=Nullable]

Remove meaningless uses of [TypeChecking=Nullable]

[TypeChecking=Nullable] only serves a purpose on nullable attributes.

Using it on interfaces without nullable attributes, or methods (even those
with nullable arguments) serves no purpose. Using it on individual
arguments also serves no purpose; in fact, the [TypeChecking] extended
attribute is not supported at all on arguments.

This patch does not change any generated code.

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=177108

[Jens Widell, 2014-06-27 13:25:03]

This leaves a grand total of 4 uses of TypeChecking=Nullable in the code.

They are all about telling the code generator that for an interface type
attribute, we can use "if (!value)" to check if the attribute is null instead of
passing an extra "bool& isNull" argument to the C++ getter.

I see no reason why we shouldn't just infer this fact from the type of the
argument instead, and drop [TypeChecking=Nullable] entirely. But, in fact, we
could drop those 4 [TypeChecking=Nullable] already, lose explicit null check in
the bindings code, and just let v8SetReturnValue() handle it, since it has a
null check too.

[haraken, 2014-06-27 14:02:10]

LGTM

[Jens Widell, 2014-06-27 14:05:10]

The CQ bit was checked by jl@opera.com

[commit-bot: I haz the power, 2014-06-27 14:05:51]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/jl@opera.com/356843007/1

[commit-bot: I haz the power, 2014-06-27 15:14:50]

Change committed as 177108