Don't use m32 cflag for x86_64.

When checking the skia_arch_type for "x86", instead of doing an
== compare, check if "x86" in skia_arch_type, so it will cover
both x86 and x86_64.

Except when we specifically want x86.

Set skia_arch_width based on "64" in skia_arch_type. No need to specify
in scripts.

In gyp_to_android.py, create a separate var_dict for x86_64.

BUG=skia:3419

Review URL: https://codereview.chromium.org/916113002
diff --git a/gyp/skia_lib.gyp b/gyp/skia_lib.gyp
index 9f61871..cc4984a 100644
--- a/gyp/skia_lib.gyp
+++ b/gyp/skia_lib.gyp
@@ -12,7 +12,7 @@
       'utils.gyp:utils',
     ],
     'conditions': [
-      [ 'skia_arch_type == "x86" and skia_os != "android"', {
+      [ '"x86" in skia_arch_type and skia_os != "android"', {
         'component_libs': [
           'opts.gyp:opts_ssse3',
           'opts.gyp:opts_sse41',