Update to Chromium revision 5fdc0fab (#520840)

- Windows now builds with clang by default.

libcef/common/crash_reporting.cc

@@ -12,6 +12,7 @@
 #include "base/debug/crash_logging.h"
 #include "base/strings/string_util.h"
 #include "chrome/common/crash_keys.h"
+#include "components/crash/core/common/crash_key.h"
 #include "content/public/common/content_switches.h"
 
 #if defined(OS_MACOSX)
@@ -161,6 +162,8 @@ void PreSandboxStartup(const base::CommandLine& command_line,
               << (process_type.empty() ? "browser" : process_type.c_str());
   }
 
+  crash_reporter::InitializeCrashKeys();
+
   // After platform crash reporting have been initialized, store the command
   // line for crash reporting.
   crash_keys::SetSwitchesFromCommandLine(command_line, &IsBoringCEFSwitch);