gyp (third_party) warning changes for ccache

Also fix a broken unit test in MatrixTest.cpp.

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2002663002

Review-Url: https://codereview.chromium.org/2002663002
diff --git a/tests/MatrixTest.cpp b/tests/MatrixTest.cpp
index 1399bf2..2f91cca 100644
--- a/tests/MatrixTest.cpp
+++ b/tests/MatrixTest.cpp
@@ -42,7 +42,7 @@
                 if (0 == aVal && 0 == bVal && aValI != bValI) {
                     foundZeroSignDiff = true;
                 } else {
-                    REPORTER_ASSERT(reporter, aVal == bVal && aValI == aValI);
+                    REPORTER_ASSERT(reporter, aVal == bVal && aValI == bValI);
                 }
             }
             REPORTER_ASSERT(reporter, foundZeroSignDiff);