MacViews: Correct behavior of move and select commands when selection direction changes.

ui/views/controls/textfield/textfield_unittest.cc

Index: ui/views/controls/textfield/textfield_unittest.cc
diff --git a/ui/views/controls/textfield/textfield_unittest.cc b/ui/views/controls/textfield/textfield_unittest.cc
index 82a712abe53994b6d757f7bd9dfd8265e9360a93..b8d02e52f7837c95d2bc05c4b492e02832727fa8 100644
--- a/ui/views/controls/textfield/textfield_unittest.cc
+++ b/ui/views/controls/textfield/textfield_unittest.cc
@@ -808,7 +808,14 @@ TEST_F(TextfieldTest, ControlAndSelectTest) {
   SendEndEvent(true);
   EXPECT_STR_EQ("two three", textfield_->GetSelectedText());
   SendHomeEvent(true);
+
+// On Mac, moving to beginning of line while selecting, extends the existing
+// selection.
+#if defined(OS_MACOSX)
+  EXPECT_STR_EQ("ZERO two three", textfield_->text());
+#else
   EXPECT_STR_EQ("ZERO ", textfield_->GetSelectedText());
+#endif
 }
 
 TEST_F(TextfieldTest, InsertionDeletionTest) {