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 7140ea1080ab370fcdde822931b4929c3acfe582..b13253999bb760835231b3c4faaa7da7e46b7a61 100644
--- a/chrome/browser/chrome_browser_main_android.h
+++ b/chrome/browser/chrome_browser_main_android.h
@@ -9,10 +9,6 @@
 #include "chrome/browser/android/chrome_backup_watcher.h"
 #include "chrome/browser/chrome_browser_main.h"
 
-namespace breakpad {
-class CrashDumpManager;
-}
-
 class ChromeBrowserMainPartsAndroid : public ChromeBrowserMainParts {
  public:
   explicit ChromeBrowserMainPartsAndroid(
@@ -30,7 +26,6 @@ class ChromeBrowserMainPartsAndroid : public ChromeBrowserMainParts {
 
  private:
   std::unique_ptr<base::MessageLoop> main_message_loop_;
-  std::unique_ptr<breakpad::CrashDumpManager> crash_dump_manager_;
   std::unique_ptr<chrome::android::ChromeBackupWatcher> backup_watcher_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeBrowserMainPartsAndroid);