Possible solution is to use UIScrollViewContentInsetAdjustmentNever like http://crrev/c/660257 but it may create other problems on iPhone X.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/5191288fe9999c8bbafc0a70dbcf44a145a023ca

commit 5191288fe9999c8bbafc0a70dbcf44a145a023ca
Author: Peter K. Lee <pkl@chromium.org>
Date: Mon Sep 18 20:37:53 2017

Sets UIScrollViewContentInsetAdjustmentNever for Open Mail Handler

Duplicated similar fix as http://crrev/c/660257 in
OpenMailHandlerViewController -viewDidLoad since the other fix will
not be cherrypicked into M62 branch but it is needed for the
OpenMailHandlerViewController.

Bug:  765146 
Change-Id: I049f5da2a34d38dfd9f1d3c6b57512b76f41e2cf
Reviewed-on: https://chromium-review.googlesource.com/671123
Commit-Queue: Peter Lee <pkl@chromium.org>
Reviewed-by: Jean-François Geyelin <jif@chromium.org>
Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Cr-Commit-Position: refs/heads/master@{#502664}
[modify] https://crrev.com/5191288fe9999c8bbafc0a70dbcf44a145a023ca/ios/chrome/browser/ui/external_app/open_mail_handler_view_controller.mm

[Auto-generated comment by a script] We noticed that this issue is targeted for M-62; it appears the fix may have landed after branch point, meaning a merge might be required. Please confirm if a merge is required here - if so add Merge-Request-62 label, otherwise remove Merge-TBD label. Thanks.

See http://crbug/755524#c33

This bug requires manual review: Less than 25 days to go before AppStore submit on M62
Please contact the milestone owner if you have questions.
Owners: amineer@(Android), cmasso@(iOS), bhthompson@(ChromeOS), abdulsyed@(Desktop)

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/f66c9a3092d77f1870d4cac487a70e9eb2f201b4

commit f66c9a3092d77f1870d4cac487a70e9eb2f201b4
Author: Peter K. Lee <pkl@chromium.org>
Date: Tue Sep 19 20:41:50 2017

Sets UIScrollViewContentInsetAdjustmentNever for Open Mail Handler

Duplicated similar fix as http://crrev/c/660257 in
OpenMailHandlerViewController -viewDidLoad since the other fix will
not be cherrypicked into M62 branch but it is needed for the
OpenMailHandlerViewController.

Bug:  765146 
Change-Id: I049f5da2a34d38dfd9f1d3c6b57512b76f41e2cf
Reviewed-on: https://chromium-review.googlesource.com/671123
Commit-Queue: Peter Lee <pkl@chromium.org>
Reviewed-by: Jean-François Geyelin <jif@chromium.org>
Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#502664}(cherry picked from commit 5191288fe9999c8bbafc0a70dbcf44a145a023ca)
Reviewed-on: https://chromium-review.googlesource.com/673008
Reviewed-by: Peter Lee <pkl@chromium.org>
Cr-Commit-Position: refs/branch-heads/3202@{#336}
Cr-Branched-From: fa6a5d87adff761bc16afc5498c3f5944c1daa68-refs/heads/master@{#499098}
[modify] https://crrev.com/f66c9a3092d77f1870d4cac487a70e9eb2f201b4/ios/chrome/browser/ui/external_app/open_mail_handler_view_controller.mm

+cmasso: Can you 

+cmasso: Can you formally approve this cherrypick which is part of the request here: https://bugs.chromium.org/p/chromium/issues/detail?id=755524#c33 ?

This bug requires manual review: Less than 24 days to go before AppStore submit on M62
Please contact the milestone owner if you have questions.
Owners: amineer@(Android), cmasso@(iOS), bhthompson@(ChromeOS), abdulsyed@(Desktop)

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

For your reference, the broken state looks like this attachment.

Deleted: 11.png 57.6 KB

	11.png 57.6 KB View Download

Thanks Peter for the screenshot.

https://drive.google.com/a/google.com/file/d/0B6GVWQnhaMClQW1jem84NjJrdDg/view?usp=sharing
Verified on iPhone 7+ iOS 11.0 , iPhone6+ iOS 10.3.3 

The text size of the three options and the toggle options are now in descending order.Also the space has been removed along with the grey.Verified on build 63.0.3219.0 Canary

This issue has been approved for a merge. Please merge the fix to any appropriate branches as soon as possible!

If all merges have been completed, please remove any remaining Merge-Approved labels from this issue.

Thanks for your time! To disable nags, add the Disable-Nags label.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Verified in iOS 10.3.3 iPhone7+, iOS 11.0 iPad Pro 12'5 in build 62.0.3202.34 beta.The space has been removed along with the grey.

Verified the issue on 62.0.3202.35 beta tested on iPad Mini(11.0).
White space has been removed, looks good. 

This issue has been approved for a merge. Please merge the fix to any appropriate branches as soon as possible!

If all merges have been completed, please remove any remaining Merge-Approved labels from this issue.

Thanks for your time! To disable nags, add the Disable-Nags label.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Merge was completed. See comment 9.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/58a6b4910cafd88be5a971e6cbd5e10171f91524

commit 58a6b4910cafd88be5a971e6cbd5e10171f91524
Author: Justin Cohen <justincohen@google.com>
Date: Wed Nov 14 19:27:19 2018

[ios] Drop iOS10 specific code.

875528, 875528, 750185, 850814

Bug: 894099,  766951 ,  836808 , 740987,  765146 ,  826369 ,  730461 ,  869176 ,
Change-Id: I07b3ab43cff3d4d4f17349fe5eff9070fef5d437
Reviewed-on: https://chromium-review.googlesource.com/c/1335207
Commit-Queue: Justin Cohen <justincohen@chromium.org>
Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Reviewed-by: Rohit Rao <rohitrao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#608075}
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/app/main_controller.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/autofill/autofill_controller_unittest.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/autofill/form_input_accessory_view.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/autofill/form_input_accessory_view_controller.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/drag_and_drop/drop_and_navigate_interaction_unittest.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/metrics/drag_and_drop_recorder.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/net/cookie_util.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/net/cookie_util_unittest.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/prerender/prerender_egtest.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/signin/gaia_auth_fetcher_ios.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/signin/gaia_auth_fetcher_ios_unittest.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/snapshots/snapshot_tab_helper.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/activity_services/activity_service_controller_egtest.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/app_launcher/open_mail_handler_view_controller.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/authentication/consent_bump/consent_bump_option_button.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/authentication/consent_bump/consent_bump_personalization_view_controller.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/authentication/consent_bump/consent_bump_view_controller.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/authentication/unified_consent/identity_chooser/identity_chooser_cell.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/authentication/unified_consent/identity_chooser/identity_chooser_presentation_controller.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/authentication/unified_consent/unified_consent_view_controller.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/autofill/manual_fill/action_cell.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/autofill/manual_fill/fallback_view_controller.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/autofill/manual_fill/manual_fill_accessory_view_controller.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/autofill/manual_fill/manual_fill_address_cell.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/autofill/manual_fill/manual_fill_card_cell.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/autofill/manual_fill/manual_fill_password_cell.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/autofill/manual_fill/password_view_controller.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/autofill/save_card_infobar_view.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/bookmarks/bookmark_edit_view_controller.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/bookmarks/bookmark_home_view_controller.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/bookmarks/bookmarks_egtest.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/browser_view_controller.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/bubble/bubble_view_unittest.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/content_suggestions/content_suggestions_coordinator.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/content_suggestions/content_suggestions_egtest.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/content_suggestions/content_suggestions_header_synchronizer.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/content_suggestions/content_suggestions_header_view.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/content_suggestions/content_suggestions_header_view_controller.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/content_suggestions/content_suggestions_layout.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/content_suggestions/content_suggestions_view_controller.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/content_suggestions/ntp_home_egtest.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/dialogs/javascript_dialog_egtest.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/find_bar/find_bar_view.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/fullscreen/fullscreen_egtest.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/fullscreen/fullscreen_system_notification_observer.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/history/history_table_view_controller.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/history/history_ui_egtest.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/infobars/confirm_infobar_view.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/main_content/web_scroll_view_main_content_ui_forwarder.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/ntp/incognito_view.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/omnibox/omnibox_text_field_ios.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/omnibox/popup/omnibox_popup_view_controller.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/overscroll_actions/overscroll_actions_controller.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/payments/cells/page_info_item.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/payments/cells/payments_selector_edit_item.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/payments/payment_request_picker_view_controller.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/popup_menu/popup_menu_presenter.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/popup_menu/popup_menu_table_view_controller.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/print/print_controller_egtest.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/qr_scanner/qr_scanner_view_controller_egtest.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/reading_list/reading_list_egtest.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/reading_list/reading_list_table_view_controller.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/recent_tabs/recent_tabs_table_view_controller.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/settings/settings_navigation_controller.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/side_swipe/card_side_swipe_view.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/tab_grid/grid/grid_view_controller.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/tab_grid/tab_grid_bottom_toolbar.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/tab_grid/tab_grid_top_toolbar.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/tab_grid/tab_grid_transition_handler.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/tab_grid/tab_grid_view_controller.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/table_view/chrome_table_view_controller.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/table_view/table_view_presentation_controller.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/tabs/tab_view.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/toolbar/adaptive_toolbar_egtest.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/toolbar/keyboard_assist/toolbar_keyboard_accessory_view.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/toolbar/primary_toolbar_view.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/toolbar/secondary_toolbar_view.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/toolbar/toolbar_egtest.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/toolbar_container/toolbar_container_view_controller.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/toolbar_container/toolbar_container_view_controller_unittest.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/util/uikit_ui_util.h
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/ui/util/uikit_ui_util.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/browser/web/cache_egtest.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/common/ui_util/BUILD.gn
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/common/ui_util/constraints_ui_util.h
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/chrome/common/ui_util/constraints_ui_util.mm
[delete] https://crrev.com/d8af30684b21a6141ab4b4e163eb300f6cb1c4af/ios/chrome/common/ui_util/constraints_ui_util_unittest.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/showcase/payments/sc_payments_picker_egtest.mm
[modify] https://crrev.com/58a6b4910cafd88be5a971e6cbd5e10171f91524/ios/showcase/test/showcase_eg_utils.mm