Update to Chromium revision 9cedf753 (#418732)

- Simplify usage of OnBeforePluginLoad (issue #2015)
- Switch crash reporting from crashpad to breakpad on Windows and OS X.
  Adds a new chrome_elf.dll dependency on Windows (issue #1995)
- Remove CefTextfield::GetPlaceholderTextColor() method which is no
  longer supported by Chromium.

libcef/common/main_delegate.h

@@ -15,6 +15,7 @@
 #include "content/public/app/content_main_delegate.h"
 
 namespace base {
+class CommandLine;
 class Thread;
 }
 
@@ -55,6 +56,11 @@ class CefMainDelegate : public content::ContentMainDelegate {
  private:
   void InitializeResourceBundle();
 
+#if defined(OS_MACOSX)
+  void InitMacCrashReporter(const base::CommandLine& command_line,
+                            const std::string& process_type);
+#endif  // defined(OS_MACOSX)
+
   std::unique_ptr<content::BrowserMainRunner> browser_runner_;
   std::unique_ptr<base::Thread> ui_thread_;