build iOS with 'make all'

This builds all skia tests by treating iOS tools
as executable applications. A few warnings were
fixed as well.

Removed old trace draw code and remnants.
Review URL: https://codereview.appspot.com/6597063

git-svn-id: http://skia.googlecode.com/svn/trunk@5776 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/tools/skdiff_main.cpp b/tools/skdiff_main.cpp
index 5fbf3ff..46d4f00 100644
--- a/tools/skdiff_main.cpp
+++ b/tools/skdiff_main.cpp
@@ -1270,7 +1270,8 @@
 const int kNoError = 0;
 const int kGenericError = -1;
 
-int main (int argc, char ** argv) {
+int tool_main(int argc, char** argv);
+int tool_main(int argc, char** argv) {
     DiffMetricProc diffProc = compute_diff_pmcolor;
     int (*sortProc)(const void*, const void*) = compare<CompareDiffMetrics>;
 
@@ -1446,3 +1447,9 @@
     // make sure that we only return 0 when there were no failures.
     return (num_failing_results > 255) ? 255 : num_failing_results;
 }
+
+#if !defined SK_BUILD_FOR_IOS
+int main(int argc, char * const argv[]) {
+    return tool_main(argc, (char**) argv);
+}
+#endif