Followup comments from https://codereview.chromium.org/298893007/

R=thakis@chromium.org

Review URL: https://codereview.chromium.org/302653009

build/gyp_pdfium

diff --git a/build/gyp_pdfium b/build/gyp_pdfium
index 59f2c6c..7019795 100755
--- a/build/gyp_pdfium
+++ b/build/gyp_pdfium
@@ -42,5 +42,6 @@
 
   run_gyp(args)
 
+
 if __name__ == '__main__':
   sys.exit(main())
\ No newline at end of file

build/standalone.gypi

diff --git a/build/standalone.gypi b/build/standalone.gypi
index ab84759..3b4f01b 100644
--- a/build/standalone.gypi
+++ b/build/standalone.gypi
@@ -37,6 +37,7 @@
       'host_arch%': '<(host_arch)',
       'target_arch%': '<(target_arch)',
     },
+    # These two are needed by V8.
     'host_arch%': '<(host_arch)',
     'target_arch%': '<(target_arch)',
     'werror%': '-Werror',
@@ -134,7 +135,7 @@
     'defines!': [
       'DEBUG',
     ],
-    'cflags!': [
+    'cflags': [
       '-Wall',
       '-W',
       '-Wno-unused-parameter',