Generate platform specific fontmgr gm.

tools/sk_tool_utils.cpp

Index: tools/sk_tool_utils.cpp
diff --git a/tools/sk_tool_utils.cpp b/tools/sk_tool_utils.cpp
index 4d0e0bde68fffcb756454a4a1bb89b044c7e859c..b06fcda3a6d8d360ee60d657cae32bc8021c6df0 100644
--- a/tools/sk_tool_utils.cpp
+++ b/tools/sk_tool_utils.cpp
@@ -10,6 +10,7 @@
 
 #include "SkBitmap.h"
 #include "SkCanvas.h"
+#include "SkCommonFlags.h"
 #include "SkShader.h"
 #include "SkTestScalerContext.h"
 #include "SkTextBlob.h"
@@ -19,6 +20,25 @@ DEFINE_bool(resourceFonts, false, "Use resource fonts");
 
 namespace sk_tool_utils {
 
+const char* platform_os_name() {
+    for (int index = 0; index < FLAGS_key.count(); index += 2) {
+        if (!strcmp("os", FLAGS_key[index])) {
+            return FLAGS_key[index + 1];
+        }
+    }
+    // when running SampleApp or dm without a --key pair, omit the platform name
+    return "";
+}
+
+const char* platform_extra_config(const char* config) {
+    for (int index = 0; index < FLAGS_key.count(); index += 2) {
+        if (!strcmp("extra_config", FLAGS_key[index]) && !strcmp(config, FLAGS_key[index + 1])) {
+            return config;
+        }
+    }
+    return "";
+}
+
 const char* colortype_name(SkColorType ct) {
     switch (ct) {
         case kUnknown_SkColorType:      return "Unknown";