The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/85d1c9a059c624f0cd459d67f4ec2028c4d7700d

commit 85d1c9a059c624f0cd459d67f4ec2028c4d7700d
Author: Alexandr Ilin <alexilin@chromium.org>
Date: Fri Jul 27 09:20:03 2018

customtabs: Detached requests for resource prefetching

This CL adds a new feature that allows the app using Chrome Custom Tabs to
prefetch resources in parallel with loading the main intent url.

The implementation reuses the DetachedResourceRequest API that was used before
for the CCTParallelRequest feature (leapfrog v2).

Bug: 866460
Change-Id: If22fbc5a430ba9cef3db69da93605eb448afa00a
Reviewed-on: https://chromium-review.googlesource.com/1146801
Reviewed-by: Yaron Friedman <yfriedman@chromium.org>
Reviewed-by: Steven Holte <holte@chromium.org>
Reviewed-by: Benoit L <lizeb@chromium.org>
Commit-Queue: Alexandr Ilin <alexilin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#578572}
[modify] https://crrev.com/85d1c9a059c624f0cd459d67f4ec2028c4d7700d/chrome/android/BUILD.gn
[modify] https://crrev.com/85d1c9a059c624f0cd459d67f4ec2028c4d7700d/chrome/android/java/src/org/chromium/chrome/browser/ChromeFeatureList.java
[modify] https://crrev.com/85d1c9a059c624f0cd459d67f4ec2028c4d7700d/chrome/android/java/src/org/chromium/chrome/browser/customtabs/ClientManager.java
[modify] https://crrev.com/85d1c9a059c624f0cd459d67f4ec2028c4d7700d/chrome/android/java/src/org/chromium/chrome/browser/customtabs/CustomTabsConnection.java
[modify] https://crrev.com/85d1c9a059c624f0cd459d67f4ec2028c4d7700d/chrome/android/javatests/src/org/chromium/chrome/browser/customtabs/DetachedResourceRequestTest.java
[modify] https://crrev.com/85d1c9a059c624f0cd459d67f4ec2028c4d7700d/chrome/browser/android/chrome_feature_list.cc
[modify] https://crrev.com/85d1c9a059c624f0cd459d67f4ec2028c4d7700d/chrome/browser/android/chrome_feature_list.h
[modify] https://crrev.com/85d1c9a059c624f0cd459d67f4ec2028c4d7700d/chrome/browser/android/customtabs/detached_resource_request.cc
[modify] https://crrev.com/85d1c9a059c624f0cd459d67f4ec2028c4d7700d/chrome/browser/android/customtabs/detached_resource_request.h
[modify] https://crrev.com/85d1c9a059c624f0cd459d67f4ec2028c4d7700d/chrome/browser/android/customtabs/detached_resource_request_android.cc
[modify] https://crrev.com/85d1c9a059c624f0cd459d67f4ec2028c4d7700d/chrome/browser/android/customtabs/detached_resource_request_unittest.cc
[modify] https://crrev.com/85d1c9a059c624f0cd459d67f4ec2028c4d7700d/tools/metrics/histograms/histograms.xml

The following revision refers to this bug:
  https://chrome-internal.googlesource.com/clank/internal/apps/+/63ba90dca2c52a94ecf682083a29443c65fd6a56

commit 63ba90dca2c52a94ecf682083a29443c65fd6a56
Author: Alexandr Ilin <alexilin@google.com>
Date: Tue Aug 07 09:33:48 2018

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/7e755bd702fe5e78f219c7fcd02fc05f4c330418

commit 7e755bd702fe5e78f219c7fcd02fc05f4c330418
Author: Alexandr Ilin <alexilin@chromium.org>
Date: Thu Aug 23 09:39:12 2018

customtabs: Enable resource prefetching feature by default

The CCTResourcePrefetch feature was approved for M70+ full stable roll-out
(https://crbug.com/856077). We keep the flag to be able to disable the feature
in case of emergency.

Bug: 866460
Change-Id: Ie010d5dc6062e30dbfe2c6b559ea01b52330ff36
Reviewed-on: https://chromium-review.googlesource.com/1186335
Reviewed-by: Benoit L <lizeb@chromium.org>
Commit-Queue: Alexandr Ilin <alexilin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#585438}
[modify] https://crrev.com/7e755bd702fe5e78f219c7fcd02fc05f4c330418/chrome/browser/android/chrome_feature_list.cc