Fix TestBrowserDialog --interactive.

It started failing in r482709 since more robust checks were added for
checking for test result output files.

To fix, remove switches::kTestLauncherOutput from the subprocess
command line so it doesn't try to create test result output.

Bug: 776265
Change-Id: Ib0406b77fb7aa90cddf712331342526fa555491b
Reviewed-on: https://chromium-review.googlesource.com/727680
Commit-Queue: Trent Apted <tapted@chromium.org>
Reviewed-by: Bret Sepulveda <bsep@chromium.org>
Cr-Commit-Position: refs/heads/master@{#510254}

chrome/browser/ui/test/browser_dialog_browsertest.cc

@@ -53,7 +53,15 @@ TEST(BrowserDialogTest, Invoke) {
   ASSERT_NE(it, dialog_cases.end()) << "Dialog '" << dialog_name
                                     << "' not found.";
 
-  base::CommandLine command(invoker);
+  // Don't create test output for the subprocess (the paths will conflict).
+  base::CommandLine::StringVector argv = invoker.argv();
+  std::string ascii(switches::kTestLauncherOutput);
+  base::CommandLine::StringType native_switch(ascii.begin(), ascii.end());
+  base::EraseIf(
+      argv, [native_switch](const base::CommandLine::StringType& arg) -> bool {
+        return arg.find(native_switch) != arg.npos;  // Substring search.
+      });
+  base::CommandLine command(argv);
 
   // Replace TestBrowserDialog.Invoke with |dialog_name|.
   command.AppendSwitchASCII(base::kGTestFilterFlag, dialog_name);