add stroke params to c api

src/c/sk_c_from_to.h

Index: src/c/sk_c_from_to.h
diff --git a/src/c/sk_c_from_to.h b/src/c/sk_c_from_to.h
new file mode 100644
index 0000000000000000000000000000000000000000..19fda37a261695e0b78fa82c77f6562ba1dea6af
--- /dev/null
+++ b/src/c/sk_c_from_to.h
@@ -0,0 +1,34 @@
+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+static bool find_sk(CType from, SKType* to) {
+    for (size_t i = 0; i < SK_ARRAY_COUNT(CTypeSkTypeMap); ++i) {
+        if (CTypeSkTypeMap[i].fC == from) {
+            if (to) {
+                *to = CTypeSkTypeMap[i].fSK;
+            }
+            return true;
+        }
+    }
+    return false;
+}
+
+static bool find_c(SKType from, CType* to) {
+    for (size_t i = 0; i < SK_ARRAY_COUNT(CTypeSkTypeMap); ++i) {
+        if (CTypeSkTypeMap[i].fSK == from) {
+            if (to) {
+                *to = CTypeSkTypeMap[i].fC;
+            }
+            return true;
+        }
+    }
+    return false;
+}
+
+#undef CType
+#undef SKType
+#undef CTypeSkTypeMap