Modify big integer library

Modify big integer library

This patch follows https://pdfium.googlesource.com/pdfium/+/44047c3300d07192a67b1714084cc2d43b1e9bd9

Modify the library to resolve compile error,
add copyright notice and change pdfium.gyp and BUILD.gn

R=tsepez@chromium.org

Committed: https://pdfium.googlesource.com/pdfium/+/91dd8c77ae849c22a8e4c9275e3f728b474b5be5

[Bo Xu, 2014-11-26 01:26:54]

bo_xu@foxitsoftware.com changed reviewers:
+ jun_fang@foxitsoftware.com, tsepez@chromium.org

[Bo Xu, 2014-11-26 01:26:54]

Hi Tom, please review the CL.

We need the BigUnsigned type and the BigIntegerUtils which converts between
string and BigInteger. The BigIntegerUtils will have some other dependencies, so
the files may look more than needed.

For exception, I use #ifdef FOXIT_CHROME_BUILD to switch between abort() and
throw.

The copyright notice would be another concern. The author has waived the
copyright, so shall we add our typical copyright or just leave it blank as it is
now?

[Tom Sepez, 2014-12-01 18:06:33]

> The copyright notice would be another concern. The author has waived the
> copyright, so shall we add our typical copyright or just leave it blank as it
is
> now?

I believe the following rules apply, but don't commit this until I get sign-off.
- The first check-in should be an unmodified copy, except for copying the README
file to a file called LICENSE.
- Unmodified code gets no additional header.
- Modified code gets the pdfium header, with an addtional comment along the
lines of
// Original code by Matt McCutchen, see the LICENSE file.

[Bo Xu, 2014-12-01 18:30:21]

On 2014/12/01 18:06:33, Tom Sepez wrote:
> > The copyright notice would be another concern. The author has waived the
> > copyright, so shall we add our typical copyright or just leave it blank as
it
> is
> > now?
> 
> I believe the following rules apply, but don't commit this until I get
sign-off.
> - The first check-in should be an unmodified copy, except for copying the
README
> file to a file called LICENSE.
> - Unmodified code gets no additional header.
> - Modified code gets the pdfium header, with an addtional comment along the
> lines of
> // Original code by Matt McCutchen, see the LICENSE file.

OK. Initial check in at https://codereview.chromium.org/773443004/

[Bo Xu, 2014-12-02 23:43:40]

Tom, this patch is the third in the row. Please take a look at the change I
made.

[Tom Sepez, 2014-12-03 00:14:19]

lgtm

https://codereview.chromium.org/754743003/diff/40001/third_party/bigint/BigIn...
File third_party/bigint/BigInteger.cc (right):

https://codereview.chromium.org/754743003/diff/40001/third_party/bigint/BigIn...
third_party/bigint/BigInteger.cc:5: // Original code by Matt McCutchen, see the
LICENSE file
nit: . at end of sentence.

https://codereview.chromium.org/754743003/diff/40001/third_party/bigint/BigUn...
File third_party/bigint/BigUnsigned.hh (right):

https://codereview.chromium.org/754743003/diff/40001/third_party/bigint/BigUn...
third_party/bigint/BigUnsigned.hh:93: using NumberlikeArray<Blk>::getCapacity;
Why do we need to do this?

[Bo Xu, 2014-12-03 00:31:22]

https://codereview.chromium.org/754743003/diff/40001/third_party/bigint/BigUn...
File third_party/bigint/BigUnsigned.hh (right):

https://codereview.chromium.org/754743003/diff/40001/third_party/bigint/BigUn...
third_party/bigint/BigUnsigned.hh:93: using NumberlikeArray<Blk>::getCapacity;
On 2014/12/03 00:14:19, Tom Sepez wrote:
> Why do we need to do this?

Otherwise the C++11 compiler complains:"ISO C+11 does not allow access
declaration; use using declarations instead".

http://stackoverflow.com/questions/24641552/xcode-5-1-1-complaining-iso-c11-d...

[Bo Xu, 2014-12-03 00:35:10]

Committed patchset #4 (id:60001) manually as
91dd8c77ae849c22a8e4c9275e3f728b474b5be5 (presubmit successful).