Support render_pdfs in iOS too (add tool_main()).

git-svn-id: http://skia.googlecode.com/svn/trunk@6254 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/tools/render_pdfs_main.cpp b/tools/render_pdfs_main.cpp
index 7815037..c103ad5 100644
--- a/tools/render_pdfs_main.cpp
+++ b/tools/render_pdfs_main.cpp
@@ -187,7 +187,9 @@
     }
 }
 
-int main(int argc, char* const argv[]) {
+int tool_main(int argc, char** argv);
+int tool_main(int argc, char** argv) {
+
     SkAutoGraphics ag;
     SkTArray<SkString> inputs;
 
@@ -209,3 +211,9 @@
     }
 }
 
+#if !defined SK_BUILD_FOR_IOS
+int main(int argc, char * const argv[]) {
+    return tool_main(argc, (char**) argv);
+}
+#endif
+