Merging latest changes from the Feed repo up to 8fb7fd9.

This merge includes the following commits:

commit 8fb7fd9a80f7512cb78178b83f017d82d04f9b14
Author:     Feed Team <no-reply@google.com>
AuthorDate: Tue Jun 30 11:24:37 2020 -0700
Commit:     Copybara-Service <copybara-worker@google.com>
CommitDate: Tue Jun 30 11:25:14 2020 -0700

    Re-add action origin filed to feed_action. This field is meant to help analyze how many actions are coming from the client side action cache versus from the active session. This will also help debug how the clients are generating duplicate actions.

    PiperOrigin-RevId: 319061509
    Change-Id: I31da37eed03b1e8b6036b12bb4000fa7e0768455

commit ea5ee1a066f16148bbbe2a687d8316d563b40a57
Author:     Travis Feuling <feuling@google.com>
AuthorDate: Tue Jun 30 09:55:58 2020 -0700
Commit:     Copybara-Service <copybara-worker@google.com>
CommitDate: Tue Jun 30 09:56:32 2020 -0700

    Export script changes.

    PiperOrigin-RevId: 319041793
    Change-Id: I46c2620b393633fee751691b6d49953c9c55c03c

Change-Id: Id516f309a883219c2918ee2a3b8e01efb4fc5ee2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2278608
Auto-Submit: Carlos Knippschild <carlosk@chromium.org>
Reviewed-by: Justin DeWitt <dewittj@chromium.org>
Commit-Queue: Carlos Knippschild <carlosk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#785896}

chrome/android/feed/merging.md

@@ -8,4 +8,4 @@ Commits that don't touch these files do not cause changes here.
 The hash below represents the last commit from that repo that was reviewed for
 the potential need to merge here.
 
-Last checked commit ID: fe33e8daa7ce3d0fd5d9d72735a9ce69f88039d1
+Last checked commit ID: 8fb7fd9a80f7512cb78178b83f017d82d04f9b14

components/feed/core/proto/wire/feed_action.proto

@@ -41,5 +41,17 @@ message FeedAction {
     // The duration for the action in milliseconds. In case of view actions this
     // is the duration for which the content is considered "viewed".
     optional int64 duration_ms = 3;
+
+    enum ActionOrigin {
+      UNKNOWN_ORIGIN = 0;
+      // Action generated from the current session on the client.
+      CLIENT_SESSION = 1;
+      // Action was previously cached on the client.
+      CLIENT_CACHE = 2;
+    }
+
+    // Where the action came from on the client.
+    // Optional: This field is purely for diagnostics.
+    optional ActionOrigin action_origin = 4;
   }
 }