[Explore Sites] Adding UMA to capture the result of the ImageDecoder service.

Change-Id: I1a5cca85ac14fcec14a6536b57d8bfa5db211fd6
Reviewed-on: https://chromium-review.googlesource.com/c/1277525
Commit-Queue: Jonathan Freed <freedjm@chromium.org>
Reviewed-by: Steven Holte <holte@chromium.org>
Reviewed-by: Justin DeWitt <dewittj@chromium.org>
Cr-Commit-Position: refs/heads/master@{#599237}

chrome/browser/android/explore_sites/image_helper.cc

@@ -5,6 +5,7 @@
 #include "chrome/browser/android/explore_sites/image_helper.h"
 
 #include "base/memory/weak_ptr.h"
+#include "base/metrics/histogram_macros.h"
 #include "chrome/browser/android/explore_sites/explore_sites_types.h"
 #include "content/public/common/service_manager_connection.h"
 #include "services/data_decoder/public/cpp/decode_image.h"
@@ -123,11 +124,17 @@ void ImageHelper::Job::DecodeImageBytes(
                             std::move(callback));
 }
 
+void RecordImageDecodedUMA(bool decoded) {
+  UMA_HISTOGRAM_BOOLEAN("ExploreSites.ImageDecoded", decoded);
+}
+
 void ImageHelper::Job::OnDecodeSiteImageDone(const SkBitmap& decoded_image) {
+  bool decode_success = !decoded_image.isNull();
   DVLOG(1) << "Decoded site image, result "
-           << (decoded_image.isNull() ? "null" : "non-null");
+           << (decode_success ? "non-null" : "null");
+  RecordImageDecodedUMA(decode_success);
 
-  if (decoded_image.isNull()) {
+  if (!decode_success) {
     std::move(bitmap_callback_).Run(nullptr);
   } else {
     std::move(bitmap_callback_).Run(std::make_unique<SkBitmap>(decoded_image));
@@ -137,10 +144,12 @@ void ImageHelper::Job::OnDecodeSiteImageDone(const SkBitmap& decoded_image) {
 
 void ImageHelper::Job::OnDecodeCategoryImageDone(
     const SkBitmap& decoded_image) {
+  bool decode_success = !decoded_image.isNull();
   DVLOG(1) << "Decoded image for category, result "
-           << (decoded_image.isNull() ? "null" : "non-null");
+           << (decode_success ? "non-null" : "null");
+  RecordImageDecodedUMA(decode_success);
 
-  if (decoded_image.isNull()) {
+  if (!decode_success) {
     num_icons_--;
   } else {
     bitmaps_.push_back(decoded_image);

chrome/browser/android/explore_sites/image_helper_unittest.cc

@@ -9,6 +9,7 @@
 
 #include "base/bind.h"
 #include "base/test/bind_test_util.h"
+#include "base/test/metrics/histogram_tester.h"
 #include "base/test/scoped_task_environment.h"
 #include "base/test/test_simple_task_runner.h"
 #include "services/data_decoder/public/cpp/test_data_decoder_service.h"
@@ -61,6 +62,8 @@ class ExploreSitesImageHelperTest : public testing::Test {
     });
   }
 
+  const base::HistogramTester& histograms() const { return histogram_tester_; }
+
   std::vector<std::unique_ptr<SkBitmap>> last_bitmap_list;
 
  protected:
@@ -71,6 +74,7 @@ class ExploreSitesImageHelperTest : public testing::Test {
   }
 
   std::unique_ptr<service_manager::TestConnectorFactory> connector_factory_;
+  base::HistogramTester histogram_tester_;
 };
 
 // 1x1 webp image with color value of 0.
@@ -271,4 +275,35 @@ TEST_F(ExploreSitesImageHelperTest, TestImageHelper_CategoryImage_InvalidWebP) {
   }
 }
 
+// Test that the ExploreSites.ImageDecoded UMA works.
+TEST_F(ExploreSitesImageHelperTest, TestImageHelper_ImageDecodedUMA) {
+  ImageHelper image_helper;
+
+  // Record one success UMA from CompseSiteImage.
+  image_helper.ComposeSiteImage(StoreBitmap(), GetEncodedImageList(1),
+                                GetConnector());
+  scoped_task_environment_.RunUntilIdle();
+
+  histograms().ExpectTotalCount("ExploreSites.ImageDecoded", 1);
+  histograms().ExpectBucketCount("ExploreSites.ImageDecoded", true, 1);
+
+  // Record one failure UMA from ComposeSiteImage.
+  EncodedImageList image_list;
+  image_list.push_back(std::make_unique<EncodedImageBytes>(kInvalidWebpBytes));
+  image_helper.ComposeSiteImage(StoreBitmap(), std::move(image_list),
+                                GetConnector());
+  scoped_task_environment_.RunUntilIdle();
+
+  histograms().ExpectTotalCount("ExploreSites.ImageDecoded", 2);
+  histograms().ExpectBucketCount("ExploreSites.ImageDecoded", false, 1);
+
+  // Record 2 samples from ComposeCategoryImage.
+  image_helper.ComposeCategoryImage(StoreBitmap(), kIconSize,
+                                    GetEncodedImageList(2), GetConnector());
+  scoped_task_environment_.RunUntilIdle();
+
+  histograms().ExpectTotalCount("ExploreSites.ImageDecoded", 4);
+  histograms().ExpectBucketCount("ExploreSites.ImageDecoded", true, 3);
+}
+
 }  // namespace explore_sites

tools/metrics/histograms/histograms.xml

@@ -28145,6 +28145,11 @@ uploading your change for review.
   </summary>
 </histogram>
 
+<histogram name="ExploreSites.ImageDecoded" units="Boolean">
+  <owner>freedjm@chromium.org</owner>
+  <summary>Tracks the result of image decoding for the favicons.</summary>
+</histogram>
+
 <histogram name="ExploreSites.MonthlyHostCount" units="hosts">
   <owner>dimich@chromium.org</owner>
   <summary>