Upboarding: Setup code directory for search tiles project.

This CL sets up the directory for query tiles upboarding project. Also
added an interface for image loader system.

Bug: 1058534
Change-Id: Id4f60ba590d5da155a30087b3db8f1e3389b55e7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2088492Reviewed-by: David Trainor <dtrainor@chromium.org>
Reviewed-by: Shakti Sahu <shaktisahu@chromium.org>
Reviewed-by: Min Qin <qinmin@chromium.org>
Reviewed-by: Hesen Zhang <hesen@chromium.org>
Commit-Queue: Xing Liu <xingliu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#747807}

chrome/browser/BUILD.gn

@@ -2976,6 +2976,7 @@ jumbo_static_library("browser") {
       "//chrome/browser/notifications/scheduler/public",
       "//chrome/browser/offline_pages/prefetch/notifications",
       "//chrome/browser/share",
+      "//chrome/browser/upboarding",
       "//chrome/browser/updates",
       "//chrome/services/media_gallery_util/public/cpp",
       "//components/autofill_assistant/browser",

chrome/browser/upboarding/BUILD.gn

+# Copyright 2020 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+group("upboarding") {
+  deps = [ "//chrome/browser/upboarding/query_tiles" ]
+}

chrome/browser/upboarding/OWNERS

+dtrainor@chromium.org
+hesen@chromium.org
+qinmin@chromium.org
+shaktisahu@chromium.org
+xingliu@chromium.org

chrome/browser/upboarding/query_tiles/BUILD.gn

+# Copyright 2020 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import("//build/config/android/config.gni")
+import("//build/config/android/rules.gni")
+
+source_set("query_tiles") {
+  deps = [ "//chrome/browser/upboarding/query_tiles/internal" ]
+}

chrome/browser/upboarding/query_tiles/internal/BUILD.gn

+# Copyright 2020 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+source_set("internal") {
+  visibility = [
+    ":*",
+    "//chrome/browser/upboarding/query_tiles:*",
+  ]
+  sources = [
+    "image_loader.cc",
+    "image_loader.h",
+  ]
+
+  deps = [
+    "//base",
+    "//skia",
+    "//url",
+  ]
+}

chrome/browser/upboarding/query_tiles/internal/image_loader.cc

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/upboarding/query_tiles/internal/image_loader.h"
+
+namespace upboarding {
+
+ImageLoader::ImageLoader() = default;
+
+ImageLoader::~ImageLoader() = default;
+
+}  // namespace upboarding

chrome/browser/upboarding/query_tiles/internal/image_loader.h

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_UPBOARDING_QUERY_TILES_INTERNAL_IMAGE_LOADER_H_
+#define CHROME_BROWSER_UPBOARDING_QUERY_TILES_INTERNAL_IMAGE_LOADER_H_
+
+#include <memory>
+#include <string>
+
+#include "base/callback.h"
+#include "base/macros.h"
+#include "url/gurl.h"
+
+class SkBitmap;
+
+namespace upboarding {
+
+// Loads image for query tiles. The image will be fetched from a URL and cached
+// on disk.
+class ImageLoader {
+ public:
+  using UpdateCallback = base::OnceCallback<bool>;
+  using DeleteCallback = base::OnceCallback<bool>;
+  using BitmapCallback = base::OnceCallback<std::unique_ptr<SkBitmap>>;
+  using Id = std::string;
+
+  ImageLoader();
+  virtual ~ImageLoader();
+
+  // Updates the image cache for a specific tile. If the URL is changed, we will
+  // immediately fetch the image, then invoke the callback.
+  virtual void Update(const Id& id,
+                      const GURL& url,
+                      UpdateCallback callback) = 0;
+  // Deletes an image cache for a specific tile.
+  virtual void Delete(const Id& id, DeleteCallback callback) = 0;
+
+  // Gets the bitmap for a specific tile. Callback will be invoked after
+  // reading the data from disk or the fetch is done.
+  void GetBitmap(const Id& id, BitmapCallback callback);
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ImageLoader);
+};
+
+}  // namespace upboarding
+
+#endif  // CHROME_BROWSER_UPBOARDING_QUERY_TILES_INTERNAL_IMAGE_LOADER_H_