Refactor CrashDump*Manager to use a shared CrashDumpObserver singleton.

chrome/browser/chrome_browser_main_android.h

Index: chrome/browser/chrome_browser_main_android.h
diff --git a/chrome/browser/chrome_browser_main_android.h b/chrome/browser/chrome_browser_main_android.h
index e2026b53a2f9c9cee7e0906efc424852b36963e8..868a71d45d1559671e8b7e118061ff2c8a2e2c79 100644
--- a/chrome/browser/chrome_browser_main_android.h
+++ b/chrome/browser/chrome_browser_main_android.h
@@ -6,6 +6,7 @@
 #define CHROME_BROWSER_CHROME_BROWSER_MAIN_ANDROID_H_
 
 #include "base/macros.h"
+#include "base/memory/ref_counted.h"
 #include "chrome/browser/chrome_browser_main.h"
 
 namespace breakpad {
@@ -29,7 +30,7 @@ class ChromeBrowserMainPartsAndroid : public ChromeBrowserMainParts {
 
  private:
   std::unique_ptr<base::MessageLoop> main_message_loop_;
-  std::unique_ptr<breakpad::CrashDumpManager> crash_dump_manager_;
+  scoped_refptr<breakpad::CrashDumpManager> crash_dump_manager_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeBrowserMainPartsAndroid);
 };