The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/e5d5c724620e2e5ea028f6369342a7d08cd998b9

commit e5d5c724620e2e5ea028f6369342a7d08cd998b9
Author: Shakti Sahu <shaktisahu@chromium.org>
Date: Fri Jun 29 02:41:13 2018

Downloads : Create offline content provider

Details :
1 - Added DownloadOfflineContentProvider class and registered it to OfflineContentAggregator.
2 - Filtered out download items from the aggregator in the Java bridge.
3 - OpenItem() and GetVisualsForItem() not yet implemented.
4 - It doesn't wait for download history is loaded currently, may be we have to do that too.

BUG: 854845
Change-Id: Id0956ec82732de2fffcda1b5e63d12f10abc8aa3
Reviewed-on: https://chromium-review.googlesource.com/1109275
Commit-Queue: Shakti Sahu <shaktisahu@chromium.org>
Reviewed-by: David Trainor <dtrainor@chromium.org>
Cr-Commit-Position: refs/heads/master@{#571367}
[add] https://crrev.com/e5d5c724620e2e5ea028f6369342a7d08cd998b9/chrome/android/java/src/org/chromium/chrome/browser/download/items/DownloadBlockedOfflineContentProvider.java
[modify] https://crrev.com/e5d5c724620e2e5ea028f6369342a7d08cd998b9/chrome/android/java/src/org/chromium/chrome/browser/download/items/OfflineContentAggregatorFactory.java
[modify] https://crrev.com/e5d5c724620e2e5ea028f6369342a7d08cd998b9/chrome/android/java_sources.gni
[modify] https://crrev.com/e5d5c724620e2e5ea028f6369342a7d08cd998b9/chrome/browser/BUILD.gn
[modify] https://crrev.com/e5d5c724620e2e5ea028f6369342a7d08cd998b9/chrome/browser/download/download_core_service_factory.cc
[modify] https://crrev.com/e5d5c724620e2e5ea028f6369342a7d08cd998b9/chrome/browser/download/download_core_service_impl.cc
[modify] https://crrev.com/e5d5c724620e2e5ea028f6369342a7d08cd998b9/chrome/browser/download/download_core_service_impl.h
[add] https://crrev.com/e5d5c724620e2e5ea028f6369342a7d08cd998b9/chrome/browser/download/download_offline_content_provider.cc
[add] https://crrev.com/e5d5c724620e2e5ea028f6369342a7d08cd998b9/chrome/browser/download/download_offline_content_provider.h
[add] https://crrev.com/e5d5c724620e2e5ea028f6369342a7d08cd998b9/chrome/browser/download/offline_item_utils.cc
[add] https://crrev.com/e5d5c724620e2e5ea028f6369342a7d08cd998b9/chrome/browser/download/offline_item_utils.h
[modify] https://crrev.com/e5d5c724620e2e5ea028f6369342a7d08cd998b9/components/offline_items_collection/core/android/java/src/org/chromium/components/offline_items_collection/LegacyHelpers.java