Remove ChromeMainDelegateAndroid::Create.

All implementations of this function do the same thing so we can just
call the constructor directly.

Change-Id: I9f1dfb6682302bf6294666895a7ffd2b716c1e58
Reviewed-on: https://chromium-review.googlesource.com/1139226
Reviewed-by: Yaron Friedman <yfriedman@chromium.org>
Commit-Queue: Peter Collingbourne <pcc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#575751}

• chrome/android/BUILD.gn[diff]
• chrome/app/android/chrome_android_initializer.cc[diff]
• chrome/app/android/chrome_main_delegate_android.h[diff]
• chrome/app/android/chrome_main_delegate_android_initializer.cc[Deleted - diff]
• chrome/browser/android/chrome_sync_shell_main_delegate_initializer.cc[Deleted - diff]