Implement manifest icon downloader

chrome/browser/manifest/manifest_icon_downloader_unittest.cc

+// Copyright 2015 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/manifest/manifest_icon_downloader.h"
+
+#include <string>
+#include <vector>
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+class ManifestIconDownloaderTest : public testing::Test  {
+ protected:
+  ManifestIconDownloaderTest() = default;
+  ~ManifestIconDownloaderTest() override = default;
+
+  int FindBitmap(const int ideal_icon_size_in_px,
+                 const int minimum_icon_size_in_px,
+                 const std::vector<SkBitmap>& bitmaps) {
+    return ManifestIconDownloader::FindClosestBitmapIndex(
+        ideal_icon_size_in_px, minimum_icon_size_in_px, bitmaps);
+  }
+
+  SkBitmap CreateDummyBitmap(int width, int height) {
+    SkBitmap bitmap;
+    bitmap.allocN32Pixels(width, height);
+    bitmap.setImmutable();
+    return bitmap;
+  }
+
+  DISALLOW_COPY_AND_ASSIGN(ManifestIconDownloaderTest);
+};
+
+TEST_F(ManifestIconDownloaderTest, NoIcons) {
+  ASSERT_EQ(-1, FindBitmap(0, 0, std::vector<SkBitmap>()));
+}
+
+TEST_F(ManifestIconDownloaderTest, ExactIsChosen) {
+  std::vector<SkBitmap> vector;

[mlamouri (slow - plz ping), 2015/08/21 12:59:08]

nit: I should have seen that before but using |vector| here isn't a great idea.
Could you rename to bitmaps?

[Lalit Maganti, 2015/08/21 13:21:34]

Done.

+  vector.push_back(CreateDummyBitmap(10, 10));
+
+  ASSERT_EQ(0, FindBitmap(10, 0, vector));
+}
+
+TEST_F(ManifestIconDownloaderTest, BiggerIsChosen) {
+  std::vector<SkBitmap> vector;
+  vector.push_back(CreateDummyBitmap(20, 20));
+
+  ASSERT_EQ(0, FindBitmap(10, 0, vector));
+}
+
+TEST_F(ManifestIconDownloaderTest, SmallerBelowMinimumIsIgnored) {
+  std::vector<SkBitmap> vector;
+  vector.push_back(CreateDummyBitmap(10, 10));
+
+  ASSERT_EQ(-1, FindBitmap(20, 15, vector));
+}
+
+TEST_F(ManifestIconDownloaderTest, SmallerAboveMinimumIsChosen) {
+  std::vector<SkBitmap> vector;
+  vector.push_back(CreateDummyBitmap(15, 15));
+
+  ASSERT_EQ(0, FindBitmap(20, 15, vector));
+}
+
+TEST_F(ManifestIconDownloaderTest, ExactIsPreferredOverBigger) {
+  std::vector<SkBitmap> vector;
+  vector.push_back(CreateDummyBitmap(20, 20));
+  vector.push_back(CreateDummyBitmap(10, 10));
+
+  ASSERT_EQ(1, FindBitmap(10, 0, vector));
+}
+
+TEST_F(ManifestIconDownloaderTest, ExactIsPreferredOverSmaller) {
+  std::vector<SkBitmap> vector;
+  vector.push_back(CreateDummyBitmap(20, 20));
+  vector.push_back(CreateDummyBitmap(10, 10));
+
+  ASSERT_EQ(0, FindBitmap(20, 0, vector));
+}
+
+TEST_F(ManifestIconDownloaderTest, BiggerIsPreferredOverCloserSmaller) {
+  std::vector<SkBitmap> vector;
+  vector.push_back(CreateDummyBitmap(20, 20));
+  vector.push_back(CreateDummyBitmap(10, 10));
+
+  ASSERT_EQ(0, FindBitmap(11, 0, vector));
+}
+
+TEST_F(ManifestIconDownloaderTest, ClosestToExactIsChosen) {
+  std::vector<SkBitmap> vector;
+  vector.push_back(CreateDummyBitmap(25, 25));
+  vector.push_back(CreateDummyBitmap(20, 20));
+
+  ASSERT_EQ(1, FindBitmap(10, 0, vector));
+}
+
+TEST_F(ManifestIconDownloaderTest, MixedReturnsBiggestClosest) {
+  std::vector<SkBitmap> vector;
+  vector.push_back(CreateDummyBitmap(10, 10));
+  vector.push_back(CreateDummyBitmap(8, 8));
+  vector.push_back(CreateDummyBitmap(6, 6));
+
+  ASSERT_EQ(0, FindBitmap(9, 0, vector));
+}
+
+TEST_F(ManifestIconDownloaderTest, MixedCanReturnMiddle) {
+  std::vector<SkBitmap> vector;
+  vector.push_back(CreateDummyBitmap(10, 10));
+  vector.push_back(CreateDummyBitmap(8, 8));
+  vector.push_back(CreateDummyBitmap(6, 6));
+
+  ASSERT_EQ(1, FindBitmap(7, 0, vector));
+}
+
+TEST_F(ManifestIconDownloaderTest, NonSquareHeightIsIgnored) {
+  std::vector<SkBitmap> vector;
+  vector.push_back(CreateDummyBitmap(15, 10));
+
+  ASSERT_EQ(-1, FindBitmap(10, 0, vector));
+}
+
+TEST_F(ManifestIconDownloaderTest, NonSquareWidthIsIgnored) {

[mlamouri (slow - plz ping), 2015/08/21 12:59:08]

nit: NonSquareHeightIsIgnored/NonSquareWidthIsIgnored is confusing. Just have
NonSquareIsIgnored

[Lalit Maganti, 2015/08/21 13:21:34]

Done.

+  std::vector<SkBitmap> vector;
+  vector.push_back(CreateDummyBitmap(15, 10));
+
+  ASSERT_EQ(-1, FindBitmap(15, 0, vector));
+}