[LargeIconService] Report size of the downloaded favicon to UMA

components/favicon/core/large_icon_service_unittest.cc

Index: components/favicon/core/large_icon_service_unittest.cc
diff --git a/components/favicon/core/large_icon_service_unittest.cc b/components/favicon/core/large_icon_service_unittest.cc
index 849a185770faf9f3a497b7da9c5cd053866613be..4cc68bb02afa4a8bd10c375a81f2d41bcf91e9a5 100644
--- a/components/favicon/core/large_icon_service_unittest.cc
+++ b/components/favicon/core/large_icon_service_unittest.cc
@@ -14,6 +14,7 @@
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "base/task/cancelable_task_tracker.h"
+#include "base/test/histogram_tester.h"
 #include "base/test/mock_callback.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "components/favicon/core/favicon_client.h"
@@ -123,6 +124,7 @@ class LargeIconServiceTest : public testing::Test {
   NiceMock<MockImageFetcher>* mock_image_fetcher_;
   testing::NiceMock<MockFaviconService> mock_favicon_service_;
   LargeIconService large_icon_service_;
+  base::HistogramTester histogram_tester_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(LargeIconServiceTest);
@@ -152,6 +154,8 @@ TEST_F(LargeIconServiceTest, ShouldGetFromGoogleServer) {
 
   EXPECT_CALL(callback, Run(true));
   base::RunLoop().RunUntilIdle();
+  histogram_tester_.ExpectUniqueSample(
+      "Favicons.LargeIconService.DownloadedSize", 64, /*expected_count=*/1);
 }
 
 TEST_F(LargeIconServiceTest, ShouldTrimQueryParametersForGoogleServer) {
@@ -191,6 +195,9 @@ TEST_F(LargeIconServiceTest, ShouldNotQueryGoogleServerIfInvalidScheme) {
 
   EXPECT_CALL(callback, Run(false));
   base::RunLoop().RunUntilIdle();
+  // No download histogram recorded.
+  histogram_tester_.ExpectUniqueSample(
+      "Favicons.LargeIconService.DownloadedSize", 0, /*expected_count=*/0);
 }
 
 TEST_F(LargeIconServiceTest, ShouldReportUnavailableIfFetchFromServerFails) {
@@ -216,6 +223,8 @@ TEST_F(LargeIconServiceTest, ShouldReportUnavailableIfFetchFromServerFails) {
 
   EXPECT_CALL(callback, Run(false));
   base::RunLoop().RunUntilIdle();
+  histogram_tester_.ExpectUniqueSample(
+      "Favicons.LargeIconService.DownloadedSize", 0, /*expected_count=*/1);
 }
 
 TEST_F(LargeIconServiceTest, ShoutNotGetFromGoogleServerIfUnavailable) {
@@ -240,6 +249,9 @@ TEST_F(LargeIconServiceTest, ShoutNotGetFromGoogleServerIfUnavailable) {
 
   EXPECT_CALL(callback, Run(false));
   base::RunLoop().RunUntilIdle();
+  // No download histogram recorded.
+  histogram_tester_.ExpectUniqueSample(
+      "Favicons.LargeIconService.DownloadedSize", 0, /*expected_count=*/0);
 }
 
 class LargeIconServiceGetterTest : public LargeIconServiceTest,