Fixed or silenced all warnings and turned on warnings-as-errors.

- Silence -Wheader-hygiene warning on Clang. Between fx_agg_driver.cpp
and fxjs_v8.h there are hundreds or thousands of things that depend on
"using namespace", so it is best to just suppress this warning than
fix it.
- gzguts.h: Include unistd.h on all non-Windows platforms, not just
Apple platforms. Fixes implicit include warnings on Linux.
- Added parens to silence a warning about mixing && and ||.
- Removed a check if an enum is negative. Enums can be unsigned,
generating an always-false warning. The check isn't necessary.
- Removed some statements that are just names of variables that do
nothing.

BUG=375114

Patch by Matt Giuca <mgiuca@chromium.org>

1 files changed, 1 insertions, 3 deletions

diff --git a/pdfium.gyp b/pdfium.gyp
index 26c5d72ab7..2135b2f44f 100644
--- a/pdfium.gyp
+++ b/pdfium.gyp
@@ -1,6 +1,5 @@
 {
   'variables': {
-    'win_third_party_warn_as_error': 'false',
     'pdf_use_skia%': 0,
   },
   'target_defaults': {
@@ -37,12 +36,11 @@
       ['OS=="mac"', {
         'xcode_settings': {
           'GCC_ENABLE_CPP_EXCEPTIONS': 'YES',
-          'GCC_TREAT_WARNINGS_AS_ERRORS': 'NO',    # -Werror
         },
       }],
       ['clang==1', {
         'cflags!': [
-          '-Werror',
+          '-Wheader-hygiene',
         ],
       }],
     ],