Remove unused IDS_ constants from pdfium.

Remove unused IDS_ constants from pdfium.

Along the way, I noticed that one of these is used in a header file
that isn't included anywhere and describes no actual code (JS_Console.h).

Also add missing header guards, and IWYU to resources.h

Also move a static function from a header to the new resources.cpp file.

Also fix the grammar on some of the error messages. Most of these
appear to be JS error messages destined for a JS error handler or (someday)
a console (which can remain in english), and oddly, some appear to be about
failed form validation, which smells user-facing.

Also check that the message makes sense for the point the C++ code
wants to use it, and reword accordingly.

As it turns out, these currently don't make it back to JS due to the
unimplemented JS_Error() function; this is an enabling step towards
implementing it.

R=thestig@chromium.org

Committed: https://pdfium.googlesource.com/pdfium/+/5b47dbfe85e8db4122089afa6d00264f1e973af2

[Tom Sepez, 2015-02-27 17:48:01]

tsepez@chromium.org changed reviewers:
+ thestig@chromium.org

[Tom Sepez, 2015-02-27 17:48:02]

Lei, for review.
Bruce, FYI.

[Lei Zhang, 2015-02-27 21:34:02]

lgtm

https://codereview.chromium.org/955273003/diff/20001/fpdfsdk/src/javascript/r...
File fpdfsdk/src/javascript/resource.cpp (right):

https://codereview.chromium.org/955273003/diff/20001/fpdfsdk/src/javascript/r...
fpdfsdk/src/javascript/resource.cpp:22: return L"The input value can't be parsed
as a valid date/time (%s).";
80 chars

[Tom Sepez, 2015-02-27 21:48:32]

https://codereview.chromium.org/955273003/diff/20001/fpdfsdk/src/javascript/r...
File fpdfsdk/src/javascript/resource.cpp (right):

https://codereview.chromium.org/955273003/diff/20001/fpdfsdk/src/javascript/r...
fpdfsdk/src/javascript/resource.cpp:22: return L"The input value can't be parsed
as a valid date/time (%s).";
On 2015/02/27 21:34:02, Lei Zhang wrote:
> 80 chars

This one fits at tabs ==4 but the next one doesn't.  I'll kill the tabs  which
got copied from the .h.

[Tom Sepez, 2015-02-27 21:48:42]

Committed patchset #3 (id:40001) manually as
5b47dbfe85e8db4122089afa6d00264f1e973af2 (presubmit successful).