Attempt to fix some -Woverloaded-virtual warnings.

Attempt to fix some -Woverloaded-virtual warnings.

There are many warnings that look like:

error: 'CPWL_RadioButton::OnChar' hides overloaded virtual function [-Werror,-Woverloaded-virtual]
        virtual FX_BOOL                         OnChar(FX_WORD nChar);
                                                ^
note: hidden overloaded virtual function 'CPWL_Wnd::OnChar' declared here: different number of parameters (2 vs 1)
        virtual FX_BOOL                                 OnChar(FX_WORD nChar, FX_DWORD nFlag);
                                                        ^

It looks like someone added the nFlag parameter to the methods in CPWL_Wnd
at some point and missed to update all overloads This patch attempts to fix this:
It adds the parameter to all methods that look like they're trying to overload the base
class method, and renames the method in one case where it fairly clearly looks like
that it's not supposed to be an overload.

BUG=pdfium:29
R=bo_xu@foxitsoftware.com

Committed: https://pdfium.googlesource.com/pdfium/+/f1d18bb

[Nico, 2014-07-30 01:22:52]

Please take a very careful look – this likely changes behavior, but since I'm
not familiar with the code, I don't know which behavior it would change. Ideally
check with whoever added the parameter to the base class.

[Bo Xu, 2014-07-30 21:14:58]

On 2014/07/30 01:22:52, Nico (away) wrote:
> Please take a very careful look – this likely changes behavior, but since
I'm
> not familiar with the code, I don't know which behavior it would change.
Ideally
> check with whoever added the parameter to the base class.

Dev team who are familiar with code check this, should be ok. lgtm

[Nico, 2014-07-30 21:17:28]

Committed patchset #1 manually as rf1d18bb (presubmit successful).