Print stack traces in child processes when browser tests failed.

base/process/launch.h

Index: base/process/launch.h
diff --git a/base/process/launch.h b/base/process/launch.h
index 0e42cd006ff0c6aabc59bf3e4a1bfe5e22f74e70..e17cee528135ab1ca37d7642f91fba0995bbf2a3 100644
--- a/base/process/launch.h
+++ b/base/process/launch.h
@@ -236,7 +236,7 @@ BASE_EXPORT bool SetJobObjectLimitFlags(HANDLE job_object, DWORD limit_flags);
 
 // Output multi-process printf, cout, cerr, etc to the cmd.exe console that ran
 // chrome. This is not thread-safe: only call from main thread.
-BASE_EXPORT void RouteStdioToConsole();
+BASE_EXPORT void RouteStdioToConsole(bool create_console_if_not_found);
 #endif  // defined(OS_WIN)
 
 // Executes the application specified by |cl| and wait for it to exit. Stores
@@ -245,6 +245,10 @@ BASE_EXPORT void RouteStdioToConsole();
 // indicating success).
 BASE_EXPORT bool GetAppOutput(const CommandLine& cl, std::string* output);
 
+// Like GetAppOutput, but also includes stderr.
+BASE_EXPORT bool GetAppOutputAndError(const CommandLine& cl,
+                                      std::string* output);
+
 #if defined(OS_WIN)
 // A Windows-specific version of GetAppOutput that takes a command line string
 // instead of a CommandLine object. Useful for situations where you need to