Patch for bug 74983 (among others) to be applied to M11 696 branch.

content/common/file_path_watcher/file_path_watcher_browsertest.cc

-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "chrome/browser/file_path_watcher/file_path_watcher.h"
+#include "content/common/file_path_watcher/file_path_watcher.h"
 
 #include <set>
 
+#if defined(OS_WIN)
+#include <windows.h>
+#include <aclapi.h>
+#elif defined(OS_POSIX)
+#include <sys/stat.h>
+#endif
+
 #include "base/basictypes.h"
+#include "base/compiler_specific.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
 #include "base/message_loop.h"
 #include "base/message_loop_proxy.h"
 #include "base/path_service.h"
 #include "base/scoped_temp_dir.h"
 #include "base/string_util.h"
 #include "base/stl_util-inl.h"
 #include "base/synchronization/waitable_event.h"
+#include "base/test/test_timeouts.h"
+#include "base/threading/thread.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
-#if defined(OS_MACOSX)
-// TODO(mnissler): There are flakes on Mac (http://crbug.com/54822) at least for
-// FilePathWatcherTest.MultipleWatchersSingleFile.
-#define MAYBE(name) FLAKY_ ## name
-#else
-#define MAYBE(name) name
-#endif
-
 namespace {
 
 class TestDelegate;
 
 // Aggregates notifications from the test delegates and breaks the message loop
 // the test thread is waiting on once they all came in.
 class NotificationCollector
     : public base::RefCountedThreadSafe<NotificationCollector> {
  public:
   NotificationCollector()
       : loop_(base::MessageLoopProxy::CreateForCurrentThread()) {}
 
   // Called from the file thread by the delegates.
   void OnChange(TestDelegate* delegate) {
     loop_->PostTask(FROM_HERE,
                     NewRunnableMethod(this,
                                       &NotificationCollector::RecordChange,
                                       make_scoped_refptr(delegate)));
   }
 
   void Register(TestDelegate* delegate) {
     delegates_.insert(delegate);
   }
 
   void Reset() {
     signaled_.clear();
   }
 
+  bool Success() {
+    return signaled_ == delegates_;
+  }
+
  private:
   void RecordChange(TestDelegate* delegate) {
     ASSERT_TRUE(loop_->BelongsToCurrentThread());
     ASSERT_TRUE(delegates_.count(delegate));
     signaled_.insert(delegate);
 
     // Check whether all delegates have been signaled.
     if (signaled_ == delegates_)
       loop_->PostTask(FROM_HERE, new MessageLoop::QuitTask());
   }
@@ skipping 19 matching lines @@
   // guarantee |loop| outlives the file thread on which OnFilePathChanged runs.
   explicit TestDelegate(NotificationCollector* collector)
       : collector_(collector) {
     collector_->Register(this);
   }
 
   virtual void OnFilePathChanged(const FilePath&) {
     collector_->OnChange(this);
   }
 
+  virtual void OnFilePathError(const FilePath& path) {
+    ADD_FAILURE() << "Error " << path.value();
+  }
+
  private:
   scoped_refptr<NotificationCollector> collector_;
 
   DISALLOW_COPY_AND_ASSIGN(TestDelegate);
 };
 
 // A helper class for setting up watches on the file thread.
 class SetupWatchTask : public Task {
  public:
   SetupWatchTask(const FilePath& target,
@@ skipping 17 matching lines @@
   FilePathWatcher* watcher_;
   FilePathWatcher::Delegate* delegate_;
   bool* result_;
   base::WaitableEvent* completion_;
 
   DISALLOW_COPY_AND_ASSIGN(SetupWatchTask);
 };
 
 class FilePathWatcherTest : public testing::Test {
  public:
-  // Implementation of FilePathWatcher on Mac requires UI loop.
   FilePathWatcherTest()
-      : loop_(MessageLoop::TYPE_UI),
-        ui_thread_(BrowserThread::UI, &loop_) {
-  }
+      : file_thread_("FilePathWatcherTest") {}
+
+  virtual ~FilePathWatcherTest() {}
 
  protected:
   virtual void SetUp() {
     // Create a separate file thread in order to test proper thread usage.
-    file_thread_.reset(new BrowserThread(BrowserThread::FILE));
-    file_thread_->Start();
-    temp_dir_.reset(new ScopedTempDir);
-    ASSERT_TRUE(temp_dir_->CreateUniqueTempDir());
+    base::Thread::Options options(MessageLoop::TYPE_IO, 0);
+    ASSERT_TRUE(file_thread_.StartWithOptions(options));
+    ASSERT_TRUE(temp_dir_.CreateUniqueTempDir());
     collector_ = new NotificationCollector();
   }
 
   virtual void TearDown() {
     loop_.RunAllPending();
-    file_thread_.reset();
   }
 
   FilePath test_file() {
-    return temp_dir_->path().AppendASCII("FilePathWatcherTest");
+    return temp_dir_.path().AppendASCII("FilePathWatcherTest");
   }
 
   // Write |content| to |file|. Returns true on success.
   bool WriteFile(const FilePath& file, const std::string& content) {
     int write_size = file_util::WriteFile(file, content.c_str(),
                                           content.length());
     return write_size == static_cast<int>(content.length());
   }
 
-  void SetupWatch(const FilePath& target,
+  bool SetupWatch(const FilePath& target,
                   FilePathWatcher* watcher,
-                  FilePathWatcher::Delegate* delegate) {
+                  FilePathWatcher::Delegate* delegate) WARN_UNUSED_RESULT {
     base::WaitableEvent completion(false, false);
     bool result;
-    BrowserThread::PostTask(BrowserThread::FILE, FROM_HERE,
-         new SetupWatchTask(target, watcher, delegate, &result, &completion));
+    file_thread_.message_loop_proxy()->PostTask(FROM_HERE,
+         new SetupWatchTask(target,
+                            watcher,
+                            delegate,
+                            &result,
+                            &completion));
     completion.Wait();
-    ASSERT_TRUE(result);
+    return result;
   }
 
-  void WaitForEvents() {
+  bool WaitForEvents() WARN_UNUSED_RESULT {
     collector_->Reset();
     loop_.Run();
+    return collector_->Success();
   }
 
   NotificationCollector* collector() { return collector_.get(); }
 
   MessageLoop loop_;
-  BrowserThread ui_thread_;
-  scoped_ptr<BrowserThread> file_thread_;
-  scoped_ptr<ScopedTempDir> temp_dir_;
+  base::Thread file_thread_;
+  ScopedTempDir temp_dir_;
   scoped_refptr<NotificationCollector> collector_;
 };
 
 // Basic test: Create the file and verify that we notice.
-TEST_F(FilePathWatcherTest, MAYBE(NewFile)) {
+TEST_F(FilePathWatcherTest, NewFile) {
   FilePathWatcher watcher;
   scoped_refptr<TestDelegate> delegate(new TestDelegate(collector()));
-  SetupWatch(test_file(), &watcher, delegate.get());
+  ASSERT_TRUE(SetupWatch(test_file(), &watcher, delegate.get()));
 
   ASSERT_TRUE(WriteFile(test_file(), "content"));
-  WaitForEvents();
+  ASSERT_TRUE(WaitForEvents());
 }
 
 // Verify that modifying the file is caught.
-TEST_F(FilePathWatcherTest, MAYBE(ModifiedFile)) {
+TEST_F(FilePathWatcherTest, ModifiedFile) {
   ASSERT_TRUE(WriteFile(test_file(), "content"));
 
   FilePathWatcher watcher;
   scoped_refptr<TestDelegate> delegate(new TestDelegate(collector()));
-  SetupWatch(test_file(), &watcher, delegate.get());
+  ASSERT_TRUE(SetupWatch(test_file(), &watcher, delegate.get()));
 
   // Now make sure we get notified if the file is modified.
   ASSERT_TRUE(WriteFile(test_file(), "new content"));
-  WaitForEvents();
+  ASSERT_TRUE(WaitForEvents());
 }
 
 // Verify that moving the file into place is caught.
-TEST_F(FilePathWatcherTest, MAYBE(MovedFile)) {
-  FilePath source_file(temp_dir_->path().AppendASCII("source"));
+TEST_F(FilePathWatcherTest, MovedFile) {
+  FilePath source_file(temp_dir_.path().AppendASCII("source"));
   ASSERT_TRUE(WriteFile(source_file, "content"));
 
   FilePathWatcher watcher;
   scoped_refptr<TestDelegate> delegate(new TestDelegate(collector()));
-  SetupWatch(test_file(), &watcher, delegate.get());
+  ASSERT_TRUE(SetupWatch(test_file(), &watcher, delegate.get()));
 
   // Now make sure we get notified if the file is modified.
   ASSERT_TRUE(file_util::Move(source_file, test_file()));
-  WaitForEvents();
+  ASSERT_TRUE(WaitForEvents());
 }
 
-TEST_F(FilePathWatcherTest, MAYBE(DeletedFile)) {
+TEST_F(FilePathWatcherTest, DeletedFile) {
   ASSERT_TRUE(WriteFile(test_file(), "content"));
 
   FilePathWatcher watcher;
   scoped_refptr<TestDelegate> delegate(new TestDelegate(collector()));
-  SetupWatch(test_file(), &watcher, delegate.get());
+  ASSERT_TRUE(SetupWatch(test_file(), &watcher, delegate.get()));
 
   // Now make sure we get notified if the file is deleted.
   file_util::Delete(test_file(), false);
-  WaitForEvents();
+  ASSERT_TRUE(WaitForEvents());
 }
 
 // Used by the DeleteDuringNotify test below.
 // Deletes the FilePathWatcher when it's notified.
 class Deleter : public FilePathWatcher::Delegate {
  public:
   Deleter(FilePathWatcher* watcher, MessageLoop* loop)
       : watcher_(watcher),
         loop_(loop) {
   }
 
   virtual void OnFilePathChanged(const FilePath& path) {
-    watcher_.reset(NULL);
+    watcher_.reset();
     loop_->PostTask(FROM_HERE, new MessageLoop::QuitTask());
   }
 
   scoped_ptr<FilePathWatcher> watcher_;
   MessageLoop* loop_;
 };
 
 // Verify that deleting a watcher during the callback doesn't crash.
 TEST_F(FilePathWatcherTest, DeleteDuringNotify) {
   FilePathWatcher* watcher = new FilePathWatcher;
   // Takes ownership of watcher.
   scoped_refptr<Deleter> deleter(new Deleter(watcher, &loop_));
-  SetupWatch(test_file(), watcher, deleter.get());
+  ASSERT_TRUE(SetupWatch(test_file(), watcher, deleter.get()));
 
   ASSERT_TRUE(WriteFile(test_file(), "content"));
-  WaitForEvents();
+  ASSERT_TRUE(WaitForEvents());
 
   // We win if we haven't crashed yet.
   // Might as well double-check it got deleted, too.
   ASSERT_TRUE(deleter->watcher_.get() == NULL);
 }
 
 // Verify that deleting the watcher works even if there is a pending
 // notification.
 TEST_F(FilePathWatcherTest, DestroyWithPendingNotification) {
   scoped_refptr<TestDelegate> delegate(new TestDelegate(collector()));
   FilePathWatcher* watcher = new FilePathWatcher;
-  SetupWatch(test_file(), watcher, delegate.get());
+  ASSERT_TRUE(SetupWatch(test_file(), watcher, delegate.get()));
   ASSERT_TRUE(WriteFile(test_file(), "content"));
-  BrowserThread::DeleteSoon(BrowserThread::FILE, FROM_HERE, watcher);
+  file_thread_.message_loop_proxy()->DeleteSoon(FROM_HERE, watcher);
 }
 
-TEST_F(FilePathWatcherTest, MAYBE(MultipleWatchersSingleFile)) {
+TEST_F(FilePathWatcherTest, MultipleWatchersSingleFile) {
   FilePathWatcher watcher1, watcher2;
   scoped_refptr<TestDelegate> delegate1(new TestDelegate(collector()));
   scoped_refptr<TestDelegate> delegate2(new TestDelegate(collector()));
-  SetupWatch(test_file(), &watcher1, delegate1.get());
-  SetupWatch(test_file(), &watcher2, delegate2.get());
+  ASSERT_TRUE(SetupWatch(test_file(), &watcher1, delegate1.get()));
+  ASSERT_TRUE(SetupWatch(test_file(), &watcher2, delegate2.get()));
 
   ASSERT_TRUE(WriteFile(test_file(), "content"));
-  WaitForEvents();
+  ASSERT_TRUE(WaitForEvents());
 }
 
 // Verify that watching a file whose parent directory doesn't exist yet works if
 // the directory and file are created eventually.
 TEST_F(FilePathWatcherTest, NonExistentDirectory) {
   FilePathWatcher watcher;
-  FilePath dir(temp_dir_->path().AppendASCII("dir"));
+  FilePath dir(temp_dir_.path().AppendASCII("dir"));
   FilePath file(dir.AppendASCII("file"));
   scoped_refptr<TestDelegate> delegate(new TestDelegate(collector()));
-  SetupWatch(file, &watcher, delegate.get());
+  ASSERT_TRUE(SetupWatch(file, &watcher, delegate.get()));
 
   ASSERT_TRUE(file_util::CreateDirectory(dir));
 
   ASSERT_TRUE(WriteFile(file, "content"));
+
   VLOG(1) << "Waiting for file creation";
-  WaitForEvents();
+  ASSERT_TRUE(WaitForEvents());
 
   ASSERT_TRUE(WriteFile(file, "content v2"));
   VLOG(1) << "Waiting for file change";
-  WaitForEvents();
+  ASSERT_TRUE(WaitForEvents());
 
   ASSERT_TRUE(file_util::Delete(file, false));
   VLOG(1) << "Waiting for file deletion";
-  WaitForEvents();
+  ASSERT_TRUE(WaitForEvents());
 }
 
 // Exercises watch reconfiguration for the case that directories on the path
 // are rapidly created.
 TEST_F(FilePathWatcherTest, DirectoryChain) {
-  FilePath path(temp_dir_->path());
+  FilePath path(temp_dir_.path());
   std::vector<std::string> dir_names;
   for (int i = 0; i < 20; i++) {
     std::string dir(StringPrintf("d%d", i));
     dir_names.push_back(dir);
     path = path.AppendASCII(dir);
   }
 
   FilePathWatcher watcher;
   FilePath file(path.AppendASCII("file"));
   scoped_refptr<TestDelegate> delegate(new TestDelegate(collector()));
-  SetupWatch(file, &watcher, delegate.get());
+  ASSERT_TRUE(SetupWatch(file, &watcher, delegate.get()));
 
-  FilePath sub_path(temp_dir_->path());
+  FilePath sub_path(temp_dir_.path());
   for (std::vector<std::string>::const_iterator d(dir_names.begin());
        d != dir_names.end(); ++d) {
     sub_path = sub_path.AppendASCII(*d);
     ASSERT_TRUE(file_util::CreateDirectory(sub_path));
   }
+  VLOG(1) << "Create File";
   ASSERT_TRUE(WriteFile(file, "content"));
   VLOG(1) << "Waiting for file creation";
-  WaitForEvents();
+  ASSERT_TRUE(WaitForEvents());
 
   ASSERT_TRUE(WriteFile(file, "content v2"));
   VLOG(1) << "Waiting for file modification";
-  WaitForEvents();
+  ASSERT_TRUE(WaitForEvents());
 }
 
 TEST_F(FilePathWatcherTest, DisappearingDirectory) {
   FilePathWatcher watcher;
-  FilePath dir(temp_dir_->path().AppendASCII("dir"));
+  FilePath dir(temp_dir_.path().AppendASCII("dir"));
   FilePath file(dir.AppendASCII("file"));
   ASSERT_TRUE(file_util::CreateDirectory(dir));
   ASSERT_TRUE(WriteFile(file, "content"));
   scoped_refptr<TestDelegate> delegate(new TestDelegate(collector()));
-  SetupWatch(file, &watcher, delegate.get());
+  ASSERT_TRUE(SetupWatch(file, &watcher, delegate.get()));
 
   ASSERT_TRUE(file_util::Delete(dir, true));
-  WaitForEvents();
+  ASSERT_TRUE(WaitForEvents());
 }
 
 // Tests that a file that is deleted and reappears is tracked correctly.
 TEST_F(FilePathWatcherTest, DeleteAndRecreate) {
   ASSERT_TRUE(WriteFile(test_file(), "content"));
   FilePathWatcher watcher;
   scoped_refptr<TestDelegate> delegate(new TestDelegate(collector()));
-  SetupWatch(test_file(), &watcher, delegate.get());
+  ASSERT_TRUE(SetupWatch(test_file(), &watcher, delegate.get()));
 
   ASSERT_TRUE(file_util::Delete(test_file(), false));
   VLOG(1) << "Waiting for file deletion";
-  WaitForEvents();
+  ASSERT_TRUE(WaitForEvents());
 
   ASSERT_TRUE(WriteFile(test_file(), "content"));
   VLOG(1) << "Waiting for file creation";
-  WaitForEvents();
+  ASSERT_TRUE(WaitForEvents());
 }
 
 TEST_F(FilePathWatcherTest, WatchDirectory) {
   FilePathWatcher watcher;
-  FilePath dir(temp_dir_->path().AppendASCII("dir"));
+  FilePath dir(temp_dir_.path().AppendASCII("dir"));
   FilePath file1(dir.AppendASCII("file1"));
   FilePath file2(dir.AppendASCII("file2"));
   scoped_refptr<TestDelegate> delegate(new TestDelegate(collector()));
-  SetupWatch(dir, &watcher, delegate.get());
+  ASSERT_TRUE(SetupWatch(dir, &watcher, delegate.get()));
 
   ASSERT_TRUE(file_util::CreateDirectory(dir));
   VLOG(1) << "Waiting for directory creation";
-  WaitForEvents();
+  ASSERT_TRUE(WaitForEvents());
 
   ASSERT_TRUE(WriteFile(file1, "content"));
   VLOG(1) << "Waiting for file1 creation";
-  WaitForEvents();
+  ASSERT_TRUE(WaitForEvents());
 
+#if !defined(OS_MACOSX)
+  // Mac implementation does not detect files modified in a directory.
   ASSERT_TRUE(WriteFile(file1, "content v2"));
   VLOG(1) << "Waiting for file1 modification";
-  WaitForEvents();
+  ASSERT_TRUE(WaitForEvents());
+#endif  // !OS_MACOSX
 
   ASSERT_TRUE(file_util::Delete(file1, false));
   VLOG(1) << "Waiting for file1 deletion";
-  WaitForEvents();
+  ASSERT_TRUE(WaitForEvents());
 
   ASSERT_TRUE(WriteFile(file2, "content"));
   VLOG(1) << "Waiting for file2 creation";
-  WaitForEvents();
+  ASSERT_TRUE(WaitForEvents());
 }
 
 TEST_F(FilePathWatcherTest, MoveParent) {
   FilePathWatcher file_watcher;
   FilePathWatcher subdir_watcher;
-  FilePath dir(temp_dir_->path().AppendASCII("dir"));
-  FilePath dest(temp_dir_->path().AppendASCII("dest"));
+  FilePath dir(temp_dir_.path().AppendASCII("dir"));
+  FilePath dest(temp_dir_.path().AppendASCII("dest"));
   FilePath subdir(dir.AppendASCII("subdir"));
   FilePath file(subdir.AppendASCII("file"));
   scoped_refptr<TestDelegate> file_delegate(new TestDelegate(collector()));
-  SetupWatch(file, &file_watcher, file_delegate.get());
+  ASSERT_TRUE(SetupWatch(file, &file_watcher, file_delegate.get()));
   scoped_refptr<TestDelegate> subdir_delegate(new TestDelegate(collector()));
-  SetupWatch(subdir, &subdir_watcher, subdir_delegate.get());
+  ASSERT_TRUE(SetupWatch(subdir, &subdir_watcher, subdir_delegate.get()));
 
   // Setup a directory hierarchy.
   ASSERT_TRUE(file_util::CreateDirectory(subdir));
   ASSERT_TRUE(WriteFile(file, "content"));
   VLOG(1) << "Waiting for file creation";
-  WaitForEvents();
+  ASSERT_TRUE(WaitForEvents());
 
   // Move the parent directory.
   file_util::Move(dir, dest);
   VLOG(1) << "Waiting for directory move";
-  WaitForEvents();
+  ASSERT_TRUE(WaitForEvents());
 }
 
 TEST_F(FilePathWatcherTest, MoveChild) {
   FilePathWatcher file_watcher;
   FilePathWatcher subdir_watcher;
-  FilePath source_dir(temp_dir_->path().AppendASCII("source"));
+  FilePath source_dir(temp_dir_.path().AppendASCII("source"));
   FilePath source_subdir(source_dir.AppendASCII("subdir"));
   FilePath source_file(source_subdir.AppendASCII("file"));
-  FilePath dest_dir(temp_dir_->path().AppendASCII("dest"));
+  FilePath dest_dir(temp_dir_.path().AppendASCII("dest"));
   FilePath dest_subdir(dest_dir.AppendASCII("subdir"));
   FilePath dest_file(dest_subdir.AppendASCII("file"));
 
   // Setup a directory hierarchy.
   ASSERT_TRUE(file_util::CreateDirectory(source_subdir));
   ASSERT_TRUE(WriteFile(source_file, "content"));
 
   scoped_refptr<TestDelegate> file_delegate(new TestDelegate(collector()));
-  SetupWatch(dest_file, &file_watcher, file_delegate.get());
+  ASSERT_TRUE(SetupWatch(dest_file, &file_watcher, file_delegate.get()));
   scoped_refptr<TestDelegate> subdir_delegate(new TestDelegate(collector()));
-  SetupWatch(dest_subdir, &subdir_watcher, subdir_delegate.get());
+  ASSERT_TRUE(SetupWatch(dest_subdir, &subdir_watcher, subdir_delegate.get()));
 
   // Move the directory into place, s.t. the watched file appears.
   ASSERT_TRUE(file_util::Move(source_dir, dest_dir));
-  WaitForEvents();
+  ASSERT_TRUE(WaitForEvents());
 }
 
+#if !defined(OS_LINUX)
+// Linux implementation of FilePathWatcher doesn't catch attribute changes.
+// http://crbug.com/78043
+
+// Verify that changing attributes on a file is caught
+TEST_F(FilePathWatcherTest, FileAttributesChanged) {
+  ASSERT_TRUE(WriteFile(test_file(), "content"));
+  FilePathWatcher watcher;
+  scoped_refptr<TestDelegate> delegate(new TestDelegate(collector()));
+  ASSERT_TRUE(SetupWatch(test_file(), &watcher, delegate.get()));
+
+  // Now make sure we get notified if the file is modified.
+  ASSERT_TRUE(file_util::MakeFileUnreadable(test_file()));
+  ASSERT_TRUE(WaitForEvents());
+}
+
+#endif  // !OS_LINUX
+
+enum Permission {
+  Read,
+  Write,
+  Execute
+};
+
+bool ChangeFilePermissions(const FilePath& path, Permission perm, bool allow) {
+#if defined(OS_POSIX)
+  struct stat stat_buf;
+
+  if (stat(path.value().c_str(), &stat_buf) != 0)
+    return false;
+
+  mode_t mode = 0;
+  switch (perm) {
+    case Read:
+      mode = S_IRUSR | S_IRGRP | S_IROTH;
+      break;
+    case Write:
+      mode = S_IWUSR | S_IWGRP | S_IWOTH;
+      break;
+    case Execute:
+      mode = S_IXUSR | S_IXGRP | S_IXOTH;
+      break;
+    default:
+      ADD_FAILURE() << "unknown perm " << perm;
+      return false;
+  }
+  if (allow) {
+    stat_buf.st_mode |= mode;
+  } else {
+    stat_buf.st_mode &= ~mode;
+  }
+  return chmod(path.value().c_str(), stat_buf.st_mode) == 0;
+
+#elif defined(OS_WIN)
+  PACL old_dacl;
+  PSECURITY_DESCRIPTOR security_descriptor;
+  if (GetNamedSecurityInfo(const_cast<wchar_t*>(path.value().c_str()),
+                           SE_FILE_OBJECT,
+                           DACL_SECURITY_INFORMATION, NULL, NULL, &old_dacl,
+                           NULL, &security_descriptor) != ERROR_SUCCESS)
+    return false;
+
+  DWORD mode = 0;
+  switch (perm) {
+    case Read:
+      mode = GENERIC_READ;
+      break;
+    case Write:
+      mode = GENERIC_WRITE;
+      break;
+    case Execute:
+      mode = GENERIC_EXECUTE;
+      break;
+    default:
+      ADD_FAILURE() << "unknown perm " << perm;
+      return false;
+  }
+
+  // Deny Read access for the current user.
+  EXPLICIT_ACCESS change;
+  change.grfAccessPermissions = mode;
+  change.grfAccessMode = allow ? GRANT_ACCESS : DENY_ACCESS;
+  change.grfInheritance = 0;
+  change.Trustee.pMultipleTrustee = NULL;
+  change.Trustee.MultipleTrusteeOperation = NO_MULTIPLE_TRUSTEE;
+  change.Trustee.TrusteeForm = TRUSTEE_IS_NAME;
+  change.Trustee.TrusteeType = TRUSTEE_IS_USER;
+  change.Trustee.ptstrName = L"CURRENT_USER";
+
+  PACL new_dacl;
+  if (SetEntriesInAcl(1, &change, old_dacl, &new_dacl) != ERROR_SUCCESS) {
+    LocalFree(security_descriptor);
+    return false;
+  }
+
+  DWORD rc = SetNamedSecurityInfo(const_cast<wchar_t*>(path.value().c_str()),
+                                  SE_FILE_OBJECT, DACL_SECURITY_INFORMATION,
+                                  NULL, NULL, new_dacl, NULL);
+  LocalFree(security_descriptor);
+  LocalFree(new_dacl);
+
+  return rc == ERROR_SUCCESS;
+#else
+  NOTIMPLEMENTED();
+  return false;
+#endif
+}
+
+#if defined(OS_MACOSX)
+// Linux implementation of FilePathWatcher doesn't catch attribute changes.
+// http://crbug.com/78043
+// Windows implementation of FilePathWatcher catches attribute changes that
+// don't affect the path being watched.
+// http://crbug.com/78045
+
+// Verify that changing attributes on a directory works.
+TEST_F(FilePathWatcherTest, DirAttributesChanged) {
+  FilePath test_dir1(temp_dir_.path().AppendASCII("DirAttributesChangedDir1"));
+  FilePath test_dir2(test_dir1.AppendASCII("DirAttributesChangedDir2"));
+  FilePath test_file(test_dir2.AppendASCII("DirAttributesChangedFile"));
+  // Setup a directory hierarchy.
+  ASSERT_TRUE(file_util::CreateDirectory(test_dir1));
+  ASSERT_TRUE(file_util::CreateDirectory(test_dir2));
+  ASSERT_TRUE(WriteFile(test_file, "content"));
+
+  FilePathWatcher watcher;
+  scoped_refptr<TestDelegate> delegate(new TestDelegate(collector()));
+  ASSERT_TRUE(SetupWatch(test_file, &watcher, delegate.get()));
+
+  // We should not get notified in this case as it hasn't affected our ability
+  // to access the file.
+  ASSERT_TRUE(ChangeFilePermissions(test_dir1, Read, false));
+  loop_.PostDelayedTask(FROM_HERE,
+                        new MessageLoop::QuitTask,
+                        TestTimeouts::tiny_timeout_ms());
+  ASSERT_FALSE(WaitForEvents());
+  ASSERT_TRUE(ChangeFilePermissions(test_dir1, Read, true));
+
+  // We should get notified in this case because filepathwatcher can no
+  // longer access the file
+  ASSERT_TRUE(ChangeFilePermissions(test_dir1, Execute, false));
+  ASSERT_TRUE(WaitForEvents());
+  ASSERT_TRUE(ChangeFilePermissions(test_dir1, Execute, true));
+}
+
+#endif  // OS_MACOSX
 }  // namespace