ui: Fix removing a number from the SequentialIDGenerator.

ui/base/sequential_id_generator_unittest.cc

Index: ui/base/sequential_id_generator_unittest.cc
diff --git a/ui/base/sequential_id_generator_unittest.cc b/ui/base/sequential_id_generator_unittest.cc
index 2176e277526624a8b615b493cb297a7e8314bb0f..be703bd7d3f4828c2e85798e9d87a4c2b5b2e3ce 100644
--- a/ui/base/sequential_id_generator_unittest.cc
+++ b/ui/base/sequential_id_generator_unittest.cc
@@ -38,4 +38,25 @@ TEST(SequentialIDGeneratorTest, AddRemove) {
   EXPECT_FALSE(generator.HasGeneratedIDFor(45));
 }
 
+TEST(SequentialIDGeneratorTest, RemoveMultipleNumbers) {
+  const uint32 kMinID = 4;
+  SequentialIDGenerator generator(kMinID);
+
+  EXPECT_EQ(4U, generator.GetGeneratedID(45));
+  EXPECT_EQ(5U, generator.GetGeneratedID(55));
+  EXPECT_EQ(6U, generator.GetGeneratedID(15));
+
+  generator.ReleaseNumber(45);
+  EXPECT_FALSE(generator.HasGeneratedIDFor(45));
+  generator.ReleaseNumber(15);
+  EXPECT_FALSE(generator.HasGeneratedIDFor(15));
+
+  EXPECT_EQ(5U, generator.GetGeneratedID(55));
+  EXPECT_EQ(4U, generator.GetGeneratedID(12));
+
+  generator.ReleaseNumber(12);
+  generator.ReleaseNumber(55);
+  EXPECT_EQ(4U, generator.GetGeneratedID(0));
+}
+
 }  // namespace ui