Add a percent format example

base/i18n/message_formatter_unittest.cc

Index: base/i18n/message_formatter_unittest.cc
diff --git a/base/i18n/message_formatter_unittest.cc b/base/i18n/message_formatter_unittest.cc
index a6f461370c7ffaef00f5971f63ca09139060f4d4..9a0615e069f2278a2d781a01f0b157a63af50c88 100644
--- a/base/i18n/message_formatter_unittest.cc
+++ b/base/i18n/message_formatter_unittest.cc
@@ -138,10 +138,17 @@ TEST_F(MessageFormatterTest, PluralNumberedArgsWithDate) {
 
 TEST_F(MessageFormatterTest, DateTimeAndNumber) {
   // Note that using 'mph' for all locales is not a good i18n practice.
+  // For various ways to format numbers, see
+  // http://icu-project.org/apiref/icu4c/classicu_1_1MessageFormat.html and
+  // http://icu-project.org/apiref/icu4c/classicu_1_1DecimalFormat.html
   const string16 pattern = ASCIIToUTF16(
       "At {0,time, short} on {0,date, medium}, "
       "there was {1} at building {2,number,integer}. "
-      "The speed of the wind was {3,number,###.#} mph.");
+      "The speed of the wind was {3,number,###.#} mph."
+      "It was a new record {4,number,percent} higher than the previous."
+      "It was a new record {4,number,##.#%} higher than the previous."
+      // padding example: '*' followed by a padding symbol.
+      "We were given {5,number,integer}:{6,number,*0##} for evacuation.");
 
   using icu::DateFormat;
   std::unique_ptr<DateFormat> tf(
@@ -155,10 +162,13 @@ TEST_F(MessageFormatterTest, DateTimeAndNumber) {
   expected.append(" on ");
   AppendFormattedDateTime(df, now, &expected);
   expected.append(", there was an explosion at building 3. "
-                  "The speed of the wind was 37.4 mph.");
+                  "The speed of the wind was 37.4 mph."
+                  "It was a new record 6% higher than the previous."
+                  "It was a new record 5.8% higher than the previous."
+                  "We were given 3:05 for evacuation.");
 
   EXPECT_EQ(expected, UTF16ToASCII(MessageFormatter::FormatWithNumberedArgs(
-      pattern, now, "an explosion", 3, 37.413)));
+      pattern, now, "an explosion", 3, 37.413, 0.0578, 3, 5)));
 }
 
 TEST_F(MessageFormatterTest, SelectorSingleOrMultiple) {