Content Index: Prepare for service worker UI thread core.

The thread ServiceWorkerContextCore lives on (the "core thread") will
move from the IO thread to the UI thread when the ServiceWorkerOnUI
feature is enabled.

This CL makes Content Index aware of the core thread instead of assuming
the IO thread. This makes ContentIndex* browser_tests pass when the
feature is enabled.

Bug: 824858
Change-Id: I03e81a564b27ee888a3402fdff11d8b51f3489a5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1775882Reviewed-by: Rayan Kanso <rayankans@chromium.org>
Commit-Queue: Matt Falkenhagen <falken@chromium.org>
Cr-Commit-Position: refs/heads/master@{#691787}

content/browser/content_index/content_index_database.h

@@ -80,28 +80,30 @@ class CONTENT_EXPORT ContentIndexDatabase {
                            BlockedOriginsCannotRegisterContent);
   FRIEND_TEST_ALL_PREFIXES(ContentIndexDatabaseTest, UmaRecorded);
 
-  // public method IO counterparts.
-  void AddEntryOnIO(int64_t service_worker_registration_id,
-                    const url::Origin& origin,
-                    blink::mojom::ContentDescriptionPtr description,
-                    const std::vector<SkBitmap>& icons,
-                    const GURL& launch_url,
-                    blink::mojom::ContentIndexService::AddCallback callback);
-  void DeleteEntryOnIO(
+  // public method service worker core thread counterparts.
+  void AddEntryOnCoreThread(
+      int64_t service_worker_registration_id,
+      const url::Origin& origin,
+      blink::mojom::ContentDescriptionPtr description,
+      const std::vector<SkBitmap>& icons,
+      const GURL& launch_url,
+      blink::mojom::ContentIndexService::AddCallback callback);
+  void DeleteEntryOnCoreThread(
       int64_t service_worker_registration_id,
       const url::Origin& origin,
       const std::string& entry_id,
       blink::mojom::ContentIndexService::DeleteCallback callback);
-  void GetDescriptionsOnIO(
+  void GetDescriptionsOnCoreThread(
       int64_t service_worker_registration_id,
       blink::mojom::ContentIndexService::GetDescriptionsCallback callback);
-  void GetIconsOnIO(int64_t service_worker_registration_id,
-                    const std::string& description_id,
-                    ContentIndexContext::GetIconsCallback callback);
-  void GetAllEntriesOnIO(ContentIndexContext::GetAllEntriesCallback callback);
-  void GetEntryOnIO(int64_t service_worker_registration_id,
-                    const std::string& description_id,
-                    ContentIndexContext::GetEntryCallback callback);
+  void GetIconsOnCoreThread(int64_t service_worker_registration_id,
+                            const std::string& description_id,
+                            ContentIndexContext::GetIconsCallback callback);
+  void GetAllEntriesOnCoreThread(
+      ContentIndexContext::GetAllEntriesCallback callback);
+  void GetEntryOnCoreThread(int64_t service_worker_registration_id,
+                            const std::string& description_id,
+                            ContentIndexContext::GetEntryCallback callback);
 
   // Add Callbacks.
   void DidSerializeIcons(
@@ -179,11 +181,11 @@ class CONTENT_EXPORT ContentIndexDatabase {
   ContentIndexProvider* provider_;
 
   // A map from origins to how many times it's been blocked.
-  // Must be used on the IO thread.
+  // Must be used on the service worker core thread.
   base::flat_map<url::Origin, int> blocked_origins_;
 
   scoped_refptr<ServiceWorkerContextWrapper> service_worker_context_;
-  base::WeakPtrFactory<ContentIndexDatabase> weak_ptr_factory_io_{this};
+  base::WeakPtrFactory<ContentIndexDatabase> weak_ptr_factory_core_{this};
   base::WeakPtrFactory<ContentIndexDatabase> weak_ptr_factory_ui_{this};
 
   DISALLOW_COPY_AND_ASSIGN(ContentIndexDatabase);