Extend FaviconService to support fetching favicons from a Google server

components/favicon_base/favicon_util.cc

 // Copyright 2014 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/favicon_base/favicon_util.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <cmath>
@@ skipping 68 matching lines @@
         desired_pixel_sizes.find(pixel_size.width());
     if (it == desired_pixel_sizes.end())
       continue;
 
     png_reps.push_back(gfx::ImagePNGRep(png_data[i].bitmap_data, it->second));
   }
 
   return png_reps;
 }
 
-// Returns a resampled bitmap of |desired_size| x |desired_size| by resampling
-// the best bitmap out of |input_bitmaps|.
-// ResizeBitmapByDownsamplingIfPossible() is similar to SelectFaviconFrames()
-// but it operates on bitmaps which have already been resampled via
-// SelectFaviconFrames().
-SkBitmap ResizeBitmapByDownsamplingIfPossible(
-    const std::vector<SkBitmap>& input_bitmaps,
-    int desired_size) {
-  DCHECK(!input_bitmaps.empty());
-  DCHECK_NE(0, desired_size);
-
-  SkBitmap best_bitmap;
-  for (size_t i = 0; i < input_bitmaps.size(); ++i) {
-    const SkBitmap& input_bitmap = input_bitmaps[i];
-    if (input_bitmap.width() == desired_size &&
-        input_bitmap.height() == desired_size) {
-      return input_bitmap;
-    } else if (best_bitmap.isNull()) {
-      best_bitmap = input_bitmap;
-    } else if (input_bitmap.width() >= best_bitmap.width() &&
-               input_bitmap.height() >= best_bitmap.height()) {
-      if (best_bitmap.width() < desired_size ||
-          best_bitmap.height() < desired_size) {
-        best_bitmap = input_bitmap;
-      }
-    } else {
-      if (input_bitmap.width() >= desired_size &&
-          input_bitmap.height() >= desired_size) {
-        best_bitmap = input_bitmap;
-      }
-    }
-  }
-
-  if (desired_size % best_bitmap.width() == 0 &&
-      desired_size % best_bitmap.height() == 0) {
-    // Use nearest neighbour resampling if upsampling by an integer. This
-    // makes the result look similar to the result of SelectFaviconFrames().
-    SkBitmap bitmap;
-    bitmap.allocN32Pixels(desired_size, desired_size);
-    if (!best_bitmap.isOpaque())
-      bitmap.eraseARGB(0, 0, 0, 0);
-
-    SkCanvas canvas(bitmap);
-    canvas.drawBitmapRect(
-        best_bitmap, SkRect::MakeIWH(desired_size, desired_size), NULL);
-    return bitmap;
-  }
-  return skia::ImageOperations::Resize(best_bitmap,
-                                       skia::ImageOperations::RESIZE_LANCZOS3,
-                                       desired_size,
-                                       desired_size);
-}
-
 }  // namespace
 
 std::vector<float> GetFaviconScales() {
   const float kScale1x = 1.0f;
   std::vector<ui::ScaleFactor> resource_scale_factors =
       ui::GetSupportedScaleFactors();
 
   // TODO(ios): 1.0f should not be necessary on iOS retina devices. However
   // the sync service only supports syncing 100p favicons. Until sync supports
   // other scales 100p is needed in the list of scales to retrieve and
@@ skipping 136 matching lines @@
   }
 
   bitmap_result.bitmap_data = base::RefCountedBytes::TakeVector(
       &resized_bitmap_data);
   bitmap_result.pixel_size =
       gfx::Size(desired_size_in_pixel, desired_size_in_pixel);
 
   return bitmap_result;
 }
 
+SkBitmap ResizeBitmapByDownsamplingIfPossible(
+    const std::vector<SkBitmap>& input_bitmaps,
+    int desired_size) {

[pkotwicz, 2016/12/19 00:03:29]

Now that this function is not in the anonymous namespace, you need to handle
|input_bitmaps| being empty.

You can still dcheck that |desired_size| != 0

[jkrcal, 2016/12/19 17:07:19]

Done.

+  DCHECK(!input_bitmaps.empty());
+  DCHECK_NE(0, desired_size);
+
+  SkBitmap best_bitmap;
+  for (size_t i = 0; i < input_bitmaps.size(); ++i) {
+    const SkBitmap& input_bitmap = input_bitmaps[i];
+    if (input_bitmap.width() == desired_size &&
+        input_bitmap.height() == desired_size) {
+      return input_bitmap;
+    } else if (best_bitmap.isNull()) {
+      best_bitmap = input_bitmap;
+    } else if (input_bitmap.width() >= best_bitmap.width() &&
+               input_bitmap.height() >= best_bitmap.height()) {
+      if (best_bitmap.width() < desired_size ||
+          best_bitmap.height() < desired_size) {
+        best_bitmap = input_bitmap;
+      }
+    } else {
+      if (input_bitmap.width() >= desired_size &&
+          input_bitmap.height() >= desired_size) {
+        best_bitmap = input_bitmap;
+      }
+    }
+  }
+
+  if (desired_size % best_bitmap.width() == 0 &&
+      desired_size % best_bitmap.height() == 0) {
+    // Use nearest neighbour resampling if upsampling by an integer. This
+    // makes the result look similar to the result of SelectFaviconFrames().
+    SkBitmap bitmap;
+    bitmap.allocN32Pixels(desired_size, desired_size);
+    if (!best_bitmap.isOpaque())
+      bitmap.eraseARGB(0, 0, 0, 0);
+
+    SkCanvas canvas(bitmap);
+    canvas.drawBitmapRect(
+        best_bitmap, SkRect::MakeIWH(desired_size, desired_size), NULL);
+    return bitmap;
+  }
+  return skia::ImageOperations::Resize(best_bitmap,
+                                       skia::ImageOperations::RESIZE_LANCZOS3,
+                                       desired_size,
+                                       desired_size);
+}
+
 }  // namespace favicon_base