Photo Picker dialog: Add UMA statistics.

chrome/android/java/src/org/chromium/chrome/browser/photo_picker/PickerBitmapViewHolder.java

 // 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.
 
 package org.chromium.chrome.browser.photo_picker;
 
 import android.content.res.Resources;
 import android.graphics.Bitmap;
 import android.os.AsyncTask;
+import android.os.SystemClock;
 import android.support.v7.widget.RecyclerView.ViewHolder;
 import android.text.TextUtils;
 
+import org.chromium.base.metrics.RecordHistogram;
 import org.chromium.chrome.R;
 
 import java.util.List;
+import java.util.concurrent.TimeUnit;
 
 /**
  * Holds on to a {@link PickerBitmapView} that displays information about a picker bitmap.
  */
 public class PickerBitmapViewHolder
         extends ViewHolder implements DecoderServiceHost.ImageDecodedCallback {
     // Our parent category.
     private PickerCategoryView mCategoryView;
 
     // The bitmap view we are holding on to.
@@ skipping 60 matching lines @@
         Bitmap original = mCategoryView.getHighResBitmaps().get(filePath);
         if (original != null) {
             mItemView.initialize(mBitmapDetails, original, false);
             return;
         }
 
         int size = mCategoryView.getImageSize();
         Bitmap placeholder = mCategoryView.getLowResBitmaps().get(filePath);
         if (placeholder != null) {
             // For performance stats see http://crbug.com/719919.
+            long begin = SystemClock.elapsedRealtime();
             placeholder = BitmapUtils.scale(placeholder, size, false);
+            long scaleTime = SystemClock.elapsedRealtime() - begin;
+            RecordHistogram.recordTimesHistogram(
+                    "Android.PhotoPicker.UpscaleLowResBitmap", scaleTime, TimeUnit.MILLISECONDS);
+
             mItemView.initialize(mBitmapDetails, placeholder, true);
         } else {
             mItemView.initialize(mBitmapDetails, null, true);
         }
 
         mCategoryView.getDecoderServiceHost().decodeImage(filePath, size, this);
     }
 
     /**
      * Returns the file path of the current request.
      */
     public String getFilePath() {
         return mBitmapDetails == null ? null : mBitmapDetails.getFilePath();
     }
 }