refactor duplication (shouldSkip and skip_name) into a utility function

R=caryclark@google.com, reed@google.com

Committed: https://code.google.com/p/skia/source/detail?r=10280

Review URL: https://codereview.chromium.org/19807005

git-svn-id: http://skia.googlecode.com/svn/trunk@10317 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/tools/flags/SkCommandLineFlags.cpp b/tools/flags/SkCommandLineFlags.cpp
index ed8db8e..b088b4e 100644
--- a/tools/flags/SkCommandLineFlags.cpp
+++ b/tools/flags/SkCommandLineFlags.cpp
@@ -303,3 +303,34 @@
         exit(0);
     }
 }
+
+bool SkCommandLineFlags::ShouldSkip(const SkTDArray<const char*>& strings, const char* name) {
+    int count = strings.count();
+    size_t testLen = strlen(name);
+    bool anyExclude = count == 0;
+    for (int i = 0; i < strings.count(); ++i) {
+        const char* matchName = strings[i];
+        size_t matchLen = strlen(matchName);
+        bool matchExclude, matchStart, matchEnd;
+        if ((matchExclude = matchName[0] == '~')) {
+            anyExclude = true;
+            matchName++;
+            matchLen--;
+        }
+        if ((matchStart = matchName[0] == '^')) {
+            matchName++;
+            matchLen--;
+        }
+        if ((matchEnd = matchName[matchLen - 1] == '$')) {
+            matchLen--;
+        }
+        if (matchStart ? (!matchEnd || matchLen == testLen)
+                && strncmp(name, matchName, matchLen) == 0
+                : matchEnd ? matchLen <= testLen
+                && strncmp(name + testLen - matchLen, matchName, matchLen) == 0
+                : strstr(name, matchName) != 0) {
+            return matchExclude;
+        }
+    }
+    return !anyExclude;
+}