[ChromeDriver] Delete old DevToolsPort file if it exists.

Bug: chromedriver:2446
Change-Id: I63cfdc367af8cdbfc7f116fb51a3e3148ee0a950
Reviewed-on: https://chromium-review.googlesource.com/1087803
Commit-Queue: Caleb Rouleau <crouleau@chromium.org>
Reviewed-by: John Chen <johnchen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#564803}

chrome/test/chromedriver/chrome_launcher.cc

@@ -339,8 +339,17 @@ Status LaunchDesktopChrome(URLRequestContextGetter* context_getter,
   base::ScopedTempDir user_data_dir_temp_dir;
   base::FilePath user_data_dir;
   base::ScopedTempDir extension_dir;
+  Status status = Status(kOk);
   std::vector<std::string> extension_bg_pages;
-  Status status =
+
+  if (capabilities.switches.HasSwitch("user-data-dir")) {
+    status = internal::RemoveOldDevToolsActivePortFile(base::FilePath(
+        capabilities.switches.GetSwitchValueNative("user-data-dir")));
+    if (status.IsError()) {
+      return status;
+    }
+  }
+  status =
       PrepareCommandLine(capabilities, &command, &user_data_dir_temp_dir,
                          &extension_dir, &extension_bg_pages, &user_data_dir);
   if (status.IsError())
@@ -909,4 +918,19 @@ Status ParseDevToolsActivePortFile(const base::FilePath& user_data_dir,
   return result;
 }
 
+Status RemoveOldDevToolsActivePortFile(const base::FilePath& user_data_dir) {
+  base::FilePath port_filepath = user_data_dir.Append(kDevToolsActivePort);
+  // Note that calling DeleteFile on a path that doesn't exist returns True.
+  if (base::DeleteFile(port_filepath, false)) {
+    return Status(kOk);
+  }
+  return Status(
+      kUnknownError,
+      std::string("Could not remove old devtools port file. Perhaps "
+                  "the given user-data-dir at ") +
+          user_data_dir.AsUTF8Unsafe() +
+          std::string(" is still attached to a running Chrome or Chromium "
+                      "process."));
+}
+
 }  // namespace internal

chrome/test/chromedriver/chrome_launcher.h

@@ -47,6 +47,7 @@ Status PrepareUserDataDir(
 Status ParseDevToolsActivePortFile(const base::FilePath& user_data_dir,
                                    int* port);
 Status ReadInPort(const base::FilePath& port_filepath, int* port);
+Status RemoveOldDevToolsActivePortFile(const base::FilePath& user_data_dir);
 }  // namespace internal
 
 #endif  // CHROME_TEST_CHROMEDRIVER_CHROME_LAUNCHER_H_

chrome/test/chromedriver/chrome_launcher_unittest.cc

@@ -16,6 +16,7 @@
 #include "base/path_service.h"
 #include "base/strings/string_split.h"
 #include "base/values.h"
+#include "build/build_config.h"
 #include "chrome/common/chrome_constants.h"
 #include "chrome/test/chromedriver/chrome/status.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -245,3 +246,30 @@ TEST(DesktopLauncher, ReadInPort_NoFile) {
   ASSERT_FALSE(internal::ReadInPort(temp_file, &port).IsOk());
   ASSERT_EQ(port, 1111);
 }
+
+TEST(DesktopLauncher, RemoveOldDevToolsActivePortFile_Success) {
+  base::ScopedTempDir temp_dir;
+  ASSERT_TRUE(temp_dir.CreateUniqueTempDir());
+  base::FilePath temp_file =
+      temp_dir.GetPath().Append(FILE_PATH_LITERAL("DevToolsActivePort"));
+  char data[] = "12345asdf\nblahblah";
+  base::WriteFile(temp_file, data, strlen(data));
+  ASSERT_TRUE(
+      internal::RemoveOldDevToolsActivePortFile(temp_dir.GetPath()).IsOk());
+  ASSERT_FALSE(base::PathExists(temp_file));
+  ASSERT_TRUE(base::PathExists(temp_dir.GetPath()));
+}
+
+#if defined(OS_WIN)
+TEST(DesktopLauncher, RemoveOldDevToolsActivePortFile_Failure) {
+  base::ScopedTempDir temp_dir;
+  ASSERT_TRUE(temp_dir.CreateUniqueTempDir());
+  base::FilePath temp_file =
+      temp_dir.GetPath().Append(FILE_PATH_LITERAL("DevToolsActivePort"));
+  FILE* fd = base::OpenFile(temp_file, "w");
+  ASSERT_FALSE(
+      internal::RemoveOldDevToolsActivePortFile(temp_dir.GetPath()).IsOk());
+  ASSERT_TRUE(base::PathExists(temp_file));
+  base::CloseFile(fd);
+}
+#endif

chrome/test/chromedriver/test/run_py_tests.py

@@ -2617,6 +2617,26 @@ class RemoteBrowserTest(ChromeDriverBaseTest):
     raise RuntimeError('Cannot find open port')
 
 
+class ExistingUserDataDirTest(ChromeDriverBaseTest):
+
+  def setUp(self):
+    self.user_data_dir = tempfile.mkdtemp()
+
+  def tearDown(self):
+    shutil.rmtree(self.user_data_dir, ignore_errors=True)
+
+  def testStartUpWithExistingDevToolsPortFile(self):
+    dev_tools_port_file = os.path.join(self.user_data_dir, 'DevToolsActivePort')
+    with open(dev_tools_port_file, 'w') as fd:
+      fd.write('34\n/devtools/browser/2dab5fb1-5571-40d8-a6ad-98823bc5ff84')
+    driver = self.CreateDriver(
+        chrome_switches=['user-data-dir=' + self.user_data_dir])
+    with open(dev_tools_port_file, 'r') as fd:
+      port = int(fd.readlines()[0])
+    # Ephemeral ports are always high numbers.
+    self.assertTrue(port > 100)
+
+
 class PerfTest(ChromeDriverBaseTest):
   """Tests for ChromeDriver perf."""
   def setUp(self):