fix build break on sample app

Review URL: https://codereview.chromium.org/19000005

git-svn-id: http://skia.googlecode.com/svn/trunk@10011 2bbb7eff-a529-9590-31e7-b0007b416f81

samplecode/SampleApp.cpp

@@ -725,7 +725,7 @@ static SkString getSampleTitle(const SkViewFactory* sampleFactory) {
     return title;
 }
 
-bool compareSampleTitle(const SkViewFactory* first, const SkViewFactory* second) {
+static bool compareSampleTitle(const SkViewFactory* first, const SkViewFactory* second) {
     return strcmp(getSampleTitle(first).c_str(), getSampleTitle(second).c_str()) < 0;
 }