[ash-md] WIP Added wallpaper color caching.

components/wallpaper/pref_based_wallpaper_color_cache_unittest.cc

Index: components/wallpaper/pref_based_wallpaper_color_cache_unittest.cc
diff --git a/components/wallpaper/pref_based_wallpaper_color_cache_unittest.cc b/components/wallpaper/pref_based_wallpaper_color_cache_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..64a45793235bd47a415726283ebe7a1d558ecba3
--- /dev/null
+++ b/components/wallpaper/pref_based_wallpaper_color_cache_unittest.cc
@@ -0,0 +1,72 @@
+// Copyright 2017 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 "components/wallpaper/pref_based_wallpaper_color_cache.h"
+
+#include <stdint.h>
+
+#include "components/prefs/testing_pref_service.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "third_party/skia/include/core/SkColor.h"
+
+namespace wallpaper {
+
+class PrefBasedWallpaperColorCacheTest : public testing::Test {
+ public:
+  PrefBasedWallpaperColorCacheTest();
+  ~PrefBasedWallpaperColorCacheTest() override;
+
+ protected:
+  PrefBasedWallpaperColorCache cache_;
+
+  TestingPrefServiceSimple pref_service_;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(PrefBasedWallpaperColorCacheTest);
+};
+
+PrefBasedWallpaperColorCacheTest::PrefBasedWallpaperColorCacheTest()
+    : cache_(&pref_service_) {
+  cache_.RegisterPrefs(pref_service_.registry());
+}
+
+PrefBasedWallpaperColorCacheTest::~PrefBasedWallpaperColorCacheTest() {}
+
+TEST_F(PrefBasedWallpaperColorCacheTest, ValueNotInCache) {
+  const uint32_t image_id = 10;
+  SkColor color;
+  EXPECT_FALSE(cache_.GetColor(image_id, &color));
+}
+
+TEST_F(PrefBasedWallpaperColorCacheTest, ValueIsCached) {
+  const uint32_t image_id = 10;
+  cache_.SetColor(image_id, SK_ColorRED);
+
+  SkColor color = SK_ColorBLACK;
+  EXPECT_TRUE(cache_.GetColor(image_id, &color));
+  EXPECT_EQ(SK_ColorRED, color);
+}
+
+TEST_F(PrefBasedWallpaperColorCacheTest, CacheIsPurged) {
+  const uint32_t image_1 = 1;
+  const uint32_t image_2 = 2;
+
+  cache_.SetColor(image_1, SK_ColorRED);
+  cache_.SetColor(image_2, SK_ColorBLUE);
+
+  SkColor color = SK_ColorBLACK;
+  EXPECT_FALSE(cache_.GetColor(image_1, &color));

[bshe, 2017/03/28 21:33:26]

why do you want to purge the cache? I imagine you could use it when next time
the user login or when different user use the same wallpaper?

[bruthig, 2017/03/28 21:35:51]

I don't plan to purge all entries in it.  Some should persist, but I don't want
it to grow unbounded.

[bshe, 2017/03/29 01:38:08]

I see. Although from the unit test, it looks like you invalidate previous
calculated color when a
new wallpaper displayed?

[bruthig, 2017/03/29 01:43:47]

This test was written under the assumption the cache was initialized with a max
size of 1.

+  EXPECT_TRUE(cache_.GetColor(image_2, &color));
+  EXPECT_EQ(SK_ColorRED, color);
+}
+
+TEST_F(PrefBasedWallpaperColorCacheTest, Foobar) {
+  const uint32_t image_1 = 1;
+  const uint32_t image_2 = 2;
+
+  cache_.SetColor(image_1, SK_ColorRED);
+  cache_.SetColor(image_2, SK_ColorBLUE);
+}
+
+}  // namespace wallpaper