Use FSEvents for recursive file watch on Mac

base/files/file_path_watcher_browsertest.cc

Index: base/files/file_path_watcher_browsertest.cc
diff --git a/base/files/file_path_watcher_browsertest.cc b/base/files/file_path_watcher_browsertest.cc
index 2bdcf13827c88216eb1db428780d0227a61cb5a8..8f57cadda90244316a304f1aff023eea37b0e5c7 100644
--- a/base/files/file_path_watcher_browsertest.cc
+++ b/base/files/file_path_watcher_browsertest.cc
@@ -205,9 +205,8 @@ bool FilePathWatcherTest::SetupWatch(const FilePath& target,
   bool result;
   file_thread_.message_loop_proxy()->PostTask(
       FROM_HERE,
-      base::Bind(SetupWatchCallback,
-                 target, watcher, delegate, recursive_watch, &result,
-                 &completion));
+      base::Bind(SetupWatchCallback, target, watcher, delegate, recursive_watch,
+                 &result, &completion));
   completion.Wait();
   return result;
 }
@@ -483,12 +482,17 @@ TEST_F(FilePathWatcherTest, MoveParent) {
   DeleteDelegateOnFileThread(subdir_delegate.release());
 }
 
-#if defined(OS_WIN) || defined(OS_LINUX)
 TEST_F(FilePathWatcherTest, RecursiveWatch) {
   FilePathWatcher watcher;
   FilePath dir(temp_dir_.path().AppendASCII("dir"));
   scoped_ptr<TestDelegate> delegate(new TestDelegate(collector()));
-  ASSERT_TRUE(SetupWatch(dir, &watcher, delegate.get(), true));
+  bool setup_result = SetupWatch(dir, &watcher, delegate.get(), true);
+  if (!FilePathWatcher::RecursiveWatchAvailable()) {
+    ASSERT_FALSE(setup_result);
+    DeleteDelegateOnFileThread(delegate.release());
+    return;
+  }
+  ASSERT_TRUE(setup_result);
 
   // Main directory("dir") creation.
   ASSERT_TRUE(base::CreateDirectory(dir));
@@ -536,17 +540,48 @@ TEST_F(FilePathWatcherTest, RecursiveWatch) {
   ASSERT_TRUE(WaitForEvents());
   DeleteDelegateOnFileThread(delegate.release());
 }
-#else
-TEST_F(FilePathWatcherTest, RecursiveWatch) {
+
+#if defined(OS_POSIX)
+TEST_F(FilePathWatcherTest, RecursiveWithSymLink) {
+  if (!FilePathWatcher::RecursiveWatchAvailable())
+    return;
+
   FilePathWatcher watcher;
-  FilePath dir(temp_dir_.path().AppendASCII("dir"));
+  FilePath test_dir(temp_dir_.path().AppendASCII("test_dir"));
+  ASSERT_TRUE(base::CreateDirectory(test_dir));
+  FilePath symlink(test_dir.AppendASCII("symlink"));
   scoped_ptr<TestDelegate> delegate(new TestDelegate(collector()));
-  // Only Windows/Linux support recursive watching. Other implementations
-  // should simply fail.
-  ASSERT_FALSE(SetupWatch(dir, &watcher, delegate.get(), true));
+  ASSERT_TRUE(SetupWatch(symlink, &watcher, delegate.get(), true));
+
+  // Link creation.
+  FilePath target1(temp_dir_.path().AppendASCII("target1"));
+  ASSERT_TRUE(base::CreateSymbolicLink(target1, symlink));
+  ASSERT_TRUE(WaitForEvents());
+
+  // Target1 creation.
+  ASSERT_TRUE(base::CreateDirectory(target1));
+  ASSERT_TRUE(WaitForEvents());
+
+  // Create a file in target1.
+  FilePath target1_file(target1.AppendASCII("file"));
+  ASSERT_TRUE(WriteFile(target1_file, "content"));
+  ASSERT_TRUE(WaitForEvents());
+
+  // Link change.
+  FilePath target2(temp_dir_.path().AppendASCII("target2"));
+  ASSERT_TRUE(base::CreateDirectory(target2));
+  ASSERT_TRUE(base::DeleteFile(symlink, false));
+  ASSERT_TRUE(base::CreateSymbolicLink(target2, symlink));
+  ASSERT_TRUE(WaitForEvents());
+
+  // Create a file in target2.
+  FilePath target2_file(target2.AppendASCII("file"));
+  ASSERT_TRUE(WriteFile(target2_file, "content"));
+  ASSERT_TRUE(WaitForEvents());
+
   DeleteDelegateOnFileThread(delegate.release());
 }
-#endif
+#endif  // OS_POSIX
 
 TEST_F(FilePathWatcherTest, MoveChild) {
   FilePathWatcher file_watcher;