Initial 'Extract Local' implementation.

pkg/analysis_server/lib/src/services/correction/strings.dart

Index: pkg/analysis_server/lib/src/services/correction/strings.dart
diff --git a/pkg/analysis_server/lib/src/services/correction/strings.dart b/pkg/analysis_server/lib/src/services/correction/strings.dart
index a72b6f6837bc3dbdd5e47bb23bfb4df03b3e3c6c..ff5c49584d492648e089a36aee3fed70f2c61572 100644
--- a/pkg/analysis_server/lib/src/services/correction/strings.dart
+++ b/pkg/analysis_server/lib/src/services/correction/strings.dart
@@ -42,6 +42,22 @@ int compareStrings(String a, String b) {
 }
 
 /**
+ * Counts how many times [sub] appears in [str].
+ */
+int countMatches(String str, String sub) {
+  if (isEmpty(str) || isEmpty(sub)) {
+    return 0;
+  }
+  int count = 0;
+  int idx = 0;
+  while ((idx = str.indexOf(sub, idx)) != -1) {
+    count++;
+    idx += sub.length;
+  }
+  return count;
+}
+
+/**
  * Checks if [str] is `null`, empty or is whitespace.
  */
 bool isBlank(String str) {
@@ -101,6 +117,7 @@ String removeStart(String str, String remove) {
   return str;
 }
 
+
 String repeat(String s, int n) {
   StringBuffer sb = new StringBuffer();
   for (int i = 0; i < n; i++) {