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, 0 insertions, 2 deletions

diff --git a/core/src/fxge/agg/agg23/fx_agg_driver.cpp b/core/src/fxge/agg/agg23/fx_agg_driver.cpp
index e0fd065532..c3f42bf9f9 100644
--- a/core/src/fxge/agg/agg23/fx_agg_driver.cpp
+++ b/core/src/fxge/agg/agg23/fx_agg_driver.cpp
@@ -616,7 +616,6 @@ public:
         int col_start = span_left < clip_left ? clip_left - span_left : 0;
         int col_end = (span_left + span_len) < clip_right ? span_len : (clip_right - span_left);
         dest_scan += col_start;
-        Bpp;
         if (dest_extra_alpha_scan) {
             for (int col = col_start; col < col_end; col ++) {
                 int src_alpha;
@@ -884,7 +883,6 @@ public:
         int col_start = span_left < clip_left ? clip_left - span_left : 0;
         int col_end = (span_left + span_len) < clip_right ? span_len : (clip_right - span_left);
         dest_scan += col_start * 4;
-        Bpp;
         if (dest_extra_alpha_scan) {
             for (int col = col_start; col < col_end; col ++) {
                 int src_alpha;