Revert "Query Tiles: Use TileIterator to implement TileManager::GetTile()."

This reverts commit f47c5813.

Reason for revert: The new test is failing on multiple bots, e.g.
https://ci.chromium.org/p/chromium/builders/ci/Mac10.13%20Tests/24417
https://ci.chromium.org/p/chromium/builders/ci/Mac10.10%20Tests/53585

Original change's description:
> Query Tiles: Use TileIterator to implement TileManager::GetTile().
> 
> Replace the recursive implementation with TileItartor. Also test is
> polished to cover the empty return case.
> 
> Bug: NONE
> Change-Id: Ifd86c560a89f639d4920cff88df5cca044fa83cb
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2177297
> Commit-Queue: Xing Liu <xingliu@chromium.org>
> Reviewed-by: Hesen Zhang <hesen@chromium.org>
> Reviewed-by: David Trainor <dtrainor@chromium.org>
> Reviewed-by: Shakti Sahu <shaktisahu@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#765329}

TBR=dtrainor@chromium.org,qinmin@chromium.org,shaktisahu@chromium.org,xingliu@chromium.org,hesen@chromium.org

Change-Id: I2acfc7c83b151d841dac914bb7b8195da63abdfa
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: NONE
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2181052Reviewed-by: Xianzhu Wang <wangxianzhu@chromium.org>
Commit-Queue: Xianzhu Wang <wangxianzhu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#765373}

components/query_tiles/internal/tile_manager.cc

@@ -12,7 +12,6 @@
 #include "base/task_runner.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/time.h"
-#include "components/query_tiles/internal/tile_iterator.h"
 #include "components/query_tiles/internal/tile_manager.h"
 
 namespace upboarding {
@@ -68,17 +67,32 @@ class TileManagerImpl : public TileManager {
         FROM_HERE, base::BindOnce(std::move(callback), std::move(tiles)));
   }
 
+  Tile* FindTile(const std::string& tile_id, Tile* root) {
+    if (tile_id == root->id)
+      return root;
+
+    for (auto& child : root->sub_tiles) {
+      if (child->id == tile_id)
+        return child.get();
+    }
+
+    Tile* result = nullptr;
+    for (auto& child : root->sub_tiles) {
+      result = FindTile(tile_id, child.get());
+      if (result)
+        return result;
+    }
+
+    return nullptr;
+  }
+
   void GetTile(const std::string& tile_id, TileCallback callback) override {
-    const Tile* result = nullptr;
+    Tile* result = nullptr;
     if (tile_group_ && ValidateGroup(tile_group_.get())) {
-      TileIterator it(*tile_group_, TileIterator::kAllTiles);
-      while (it.HasNext()) {
-        const auto* tile = it.Next();
-        DCHECK(tile);
-        if (tile->id == tile_id) {
-          result = tile;
+      for (const auto& tile : tile_group_->tiles) {
+        result = FindTile(tile_id, tile.get());
+        if (result)
           break;
-        }
       }
     }
 

components/query_tiles/internal/tile_manager_unittest.cc

@@ -60,29 +60,6 @@ class TileManagerTest : public testing::Test {
     loop.Run();
   }
 
-  // TODO(crbug.com/1078163): Replace Init() with InitWithData.
-  void InitWithData(TileGroupStatus expected_status,
-                    std::vector<TileGroup> groups,
-                    bool success = true) {
-    MockTileStore::KeysAndEntries entries;
-    for (const auto& group : groups) {
-      entries[group.id] = std::make_unique<TileGroup>(group);
-    }
-
-    EXPECT_CALL(*tile_store(), InitAndLoad(_))
-        .WillOnce(Invoke(
-            [&](base::OnceCallback<void(bool, MockTileStore::KeysAndEntries)>
-                    callback) {
-              std::move(callback).Run(success, std::move(entries));
-            }));
-
-    base::RunLoop loop;
-    manager()->Init(base::BindOnce(&TileManagerTest::OnInitCompleted,
-                                   base::Unretained(this), loop.QuitClosure(),
-                                   expected_status));
-    loop.Run();
-  }
-
   void OnInitCompleted(base::RepeatingClosure closure,
                        TileGroupStatus expected_status,
                        TileGroupStatus status) {
@@ -126,7 +103,7 @@ class TileManagerTest : public testing::Test {
     std::move(closure).Run();
   }
 
-  void GetSingleTile(const std::string& id, base::Optional<Tile> expected) {
+  void GetSingleTile(const std::string& id, Tile expected) {
     base::RunLoop loop;
     manager()->GetTile(
         id, base::BindOnce(&TileManagerTest::OnGetTile, base::Unretained(this),
@@ -137,9 +114,7 @@ class TileManagerTest : public testing::Test {
   void OnGetTile(base::RepeatingClosure closure,
                  base::Optional<Tile> expected,
                  base::Optional<Tile> actual) {
-    ASSERT_EQ(expected.has_value(), actual.has_value());
-    if (expected.has_value())
-      EXPECT_TRUE(test::AreTilesIdentical(expected.value(), actual.value()));
+    EXPECT_TRUE(test::AreTilesIdentical(expected.value(), actual.value()));
     std::move(closure).Run();
   }
 
@@ -243,6 +218,7 @@ TEST_F(TileManagerTest, InitAndLoadSuccess) {
 
   Init(TileGroupStatus::kSuccess);
   GetTiles(expected);
+  GetSingleTile("guid-1-1", expected[0]);
 }
 
 // Failed to init an empty db, and save tiles call failed because of db is
@@ -366,15 +342,6 @@ TEST_F(TileManagerTest, SaveTilesAndReplaceOldGroupSuccess) {
   GetTiles(std::move(expected));
 }
 
-// Verifies GetTile(tile_id) API can return the right thing.
-TEST_F(TileManagerTest, GetTileById) {
-  TileGroup group;
-  test::ResetTestGroup(&group);
-  InitWithData(TileGroupStatus::kSuccess, {group});
-  GetSingleTile("guid-1-1", *group.tiles[0]);
-  GetSingleTile("id_not_exist", base::nullopt);
-}
-
 }  // namespace
 
 }  // namespace upboarding