Enable 32/64-bit gyp switch on Linux

Linux defaults to 64, other platforms 32.  As of this change, only Mac and
Linux are affected by the skia_arch_width flag.  Next step is to make Win
work as well.
Review URL: https://codereview.appspot.com/6460066

git-svn-id: http://skia.googlecode.com/svn/trunk@5041 2bbb7eff-a529-9590-31e7-b0007b416f81

gyp/common_conditions.gypi

@@ -111,6 +111,24 @@
           '-Wno-unused-parameter',
           '-Wno-c++11-extensions'
         ],
+        'conditions' : [
+          ['skia_arch_width == 64', {
+            'cflags': [
+              '-m64',
+            ],
+            'ldflags': [
+              '-m64',
+            ],
+          }],
+          ['skia_arch_width == 32', {
+            'cflags': [
+              '-m32',
+            ],
+            'ldflags': [
+              '-m32',
+            ],
+          }],
+        ],
         'include_dirs' : [
           '/usr/include/freetype2',
         ],

gyp/common_variables.gypi

@@ -57,6 +57,11 @@
         }, {
           'os_posix%': 1,
         }],
+        ['skia_os in ["linux", "freebsd", "openbsd", "solaris"]', {
+          'skia_arch_width%': 64,
+        }, {
+          'skia_arch_width%': 32,
+        }],
       ],
 
       'skia_scalar%': 'float',
@@ -65,7 +70,6 @@
       # Do not turn on 'skia_angle' - it is currently experimental
       'skia_angle%': 0,
       'skia_arch_type%': 'x86',
-      'skia_arch_width%': 32,
       'android_make_apk%': 1,
       'skia_gpu%': 1,
     },