Add baked-in favicons for default popular sites on NTP

components/ntp_tiles/icon_cacher_impl_unittest.cc

Index: components/ntp_tiles/icon_cacher_impl_unittest.cc
diff --git a/components/ntp_tiles/icon_cacher_impl_unittest.cc b/components/ntp_tiles/icon_cacher_impl_unittest.cc
index f80289c8ae14b2fb75deb14249304bdab0ab18c4..18e20b8ec7b56ac80f8ca6eec0abd99f2f6a4067 100644
--- a/components/ntp_tiles/icon_cacher_impl_unittest.cc
+++ b/components/ntp_tiles/icon_cacher_impl_unittest.cc
@@ -18,6 +18,7 @@
 #include "components/image_fetcher/image_fetcher.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
+#include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/image/image_unittest_util.h"
 
 using ::testing::_;
@@ -41,6 +42,45 @@ class MockImageFetcher : public image_fetcher::ImageFetcher {
                                         const gfx::Image& image)> callback));
 };
 
+// This class provides methods to inject an image resource where a real resource
+// would be necessary otherwise. All other methods have return values that allow
+// the normal implementation to proceed.
+class MockResourceDelegate : public ui::ResourceBundle::Delegate {
+ public:
+  ~MockResourceDelegate() override {}
+  base::FilePath GetPathForResourcePack(const base::FilePath& pack_path,
+                                        ui::ScaleFactor scale_factor) override {
+    return pack_path;  // Continue Loading pack file.
+  }
+
+  base::FilePath GetPathForLocalePack(const base::FilePath& pack_path,
+                                      const std::string& locale) override {
+    return pack_path;  // Continue Loading pack file.
+  }
+
+  MOCK_METHOD1(GetImageNamed, gfx::Image(int));
+
+  gfx::Image GetNativeImageNamed(int resource_id) override {
+    return gfx::Image();  // Attempt retrieval of the default resource.
+  }
+
+  base::RefCountedMemory* LoadDataResourceBytes(
+      int resource_id,
+      ui::ScaleFactor scale_factor) override {
+    return nullptr;  // Attempt retrieval of the default resource.
+  }
+
+  bool GetRawDataResource(int resource_id,
+                          ui::ScaleFactor scale_factor,
+                          base::StringPiece* value) override {
+    return false;  // Attempt retrieval of the default resource.
+  }
+
+  bool GetLocalizedString(int message_id, base::string16* value) override {
+    return false;  // Attempt retrieval of the default resource.
+  }
+};
+
 class IconCacherTest : public ::testing::Test {
  protected:
   IconCacherTest()
@@ -195,5 +235,43 @@ TEST_F(IconCacherTest, LargeNotCachedAndFetchFailed) {
   EXPECT_FALSE(IconIsCachedFor(site_.url, favicon_base::TOUCH_ICON));
 }
 
+TEST_F(IconCacherTest, ProvidesDefaultIconAndSucceedsWithFetching) {
+  if (ui::ResourceBundle::HasSharedInstance()) {
+    ui::ResourceBundle::CleanupSharedInstance();
+  }
+
+  // Returns true after the global resource loader instance has been created.
+  MockResourceDelegate mock_resource;
+  ui::ResourceBundle::InitSharedInstanceWithLocale(
+      "en-US", &mock_resource, ui::ResourceBundle::LOAD_COMMON_RESOURCES);
+  MockFunction<void(bool)> done;
+  base::RunLoop loop_for_static;
+  base::RunLoop loop_for_fetch;
+  {
+    InSequence s;
+    EXPECT_CALL(*image_fetcher_,
+                SetDataUseServiceName(
+                    data_use_measurement::DataUseUserData::NTP_TILES));
+    EXPECT_CALL(mock_resource, GetImageNamed(12345))
+        .WillOnce(Return(gfx::test::CreateImage(64, 64)));
+    EXPECT_CALL(done, Call(true)).WillOnce(Quit(&loop_for_static));
+    EXPECT_CALL(*image_fetcher_,
+                StartOrQueueNetworkRequest(_, site_.large_icon_url, _))
+        .WillOnce(PassFetch(128, 128));
+    EXPECT_CALL(done, Call(true)).WillOnce(Quit(&loop_for_fetch));
+  }
+
+  IconCacherImpl cacher(&favicon_service_, std::move(image_fetcher_));
+  cacher.AddDefaultImage(site_, /*image_resource_id=*/12345);
+  cacher.StartFetch(site_, BindMockFunction(&done));
+
+  loop_for_static.Run();  // Wait for the default image.
+  EXPECT_TRUE(IconIsCachedFor(site_.url, favicon_base::TOUCH_ICON));
+
+  // Let the fetcher continue and wait for the second call of the callback.
+  loop_for_fetch.Run();  // Wait for the updated image.
+  EXPECT_TRUE(IconIsCachedFor(site_.url, favicon_base::TOUCH_ICON));
+}
+
 }  // namespace
 }  // namespace ntp_tiles