Always select best favicon bitmap

components/favicon_base/favicon_util.cc

Index: components/favicon_base/favicon_util.cc
diff --git a/components/favicon_base/favicon_util.cc b/components/favicon_base/favicon_util.cc
index d45196e2a707ae48f5fb4dfa88516966025b2505..31f1da94aa3719f0240a390a5f45823e98f31e5a 100644
--- a/components/favicon_base/favicon_util.cc
+++ b/components/favicon_base/favicon_util.cc
@@ -30,43 +30,35 @@
 namespace favicon_base {
 namespace {
 
+gfx::Image SelectLargestFrame(
+    const std::vector<favicon_base::FaviconRawBitmapResult>& png_data) {
+  if (png_data.empty())
+    return gfx::Image();
+
+  int maximum_area = 0;
+  scoped_refptr<base::RefCountedMemory> best_candidate;
+  for (size_t i = 0; i < png_data.size(); ++i) {
+    int area = png_data[i].pixel_size.GetArea();
+    if (area > maximum_area) {
+      maximum_area = area;
+      best_candidate = png_data[i].bitmap_data;
+    }
+  }
+  return gfx::Image({gfx::ImagePNGRep(best_candidate, 1.0f)});
+}
+
 // Creates image reps of DIP size |favicon_size| for the subset of
 // |favicon_scales| for which the image reps can be created without resizing
 // or decoding the bitmap data.
 std::vector<gfx::ImagePNGRep> SelectFaviconFramesFromPNGsWithoutResizing(
     const std::vector<favicon_base::FaviconRawBitmapResult>& png_data,
-    const std::vector<float>& favicon_scales,
-    int favicon_size) {
+    std::map<int, float> desired_pixel_sizes) {
   TRACE_EVENT0("browser",
                "FaviconUtil::SelectFaviconFramesFromPNGsWithoutResizing");
   std::vector<gfx::ImagePNGRep> png_reps;
   if (png_data.empty())
     return png_reps;
 
-  // A |favicon_size| of 0 indicates that the largest frame is desired.
-  if (favicon_size == 0) {
-    int maximum_area = 0;
-    scoped_refptr<base::RefCountedMemory> best_candidate;
-    for (size_t i = 0; i < png_data.size(); ++i) {
-      int area = png_data[i].pixel_size.GetArea();
-      if (area > maximum_area) {
-        maximum_area = area;
-        best_candidate = png_data[i].bitmap_data;
-      }
-    }
-    png_reps.push_back(gfx::ImagePNGRep(best_candidate, 1.0f));
-    return png_reps;
-  }
-
-  // Build a map which will be used to determine the scale used to
-  // create a bitmap with given pixel size.
-  std::map<int, float> desired_pixel_sizes;
-  for (size_t i = 0; i < favicon_scales.size(); ++i) {
-    int pixel_size =
-        static_cast<int>(std::ceil(favicon_size * favicon_scales[i]));
-    desired_pixel_sizes[pixel_size] = favicon_scales[i];
-  }
-
   for (size_t i = 0; i < png_data.size(); ++i) {
     if (!png_data[i].is_valid())
       continue;
@@ -171,6 +163,27 @@ gfx::Image SelectFaviconFramesFromPNGs(
     int favicon_size) {
   TRACE_EVENT0("browser", "FaviconUtil::SelectFaviconFramesFromPNGs");
 
+  // A |favicon_size| of 0 indicates that the largest frame is desired.
+  if (favicon_size == 0) {
+    return SelectLargestFrame(png_data);
+  }
+
+  // Build a map which will be used to determine the scale used to
+  // create a bitmap with given pixel size.
+  std::map<int, float> desired_pixel_sizes;
+  for (size_t i = 0; i < favicon_scales.size(); ++i) {
+    int pixel_size =
+        static_cast<int>(std::ceil(favicon_size * favicon_scales[i]));
+    desired_pixel_sizes[pixel_size] = favicon_scales[i];
+  }
+
+  return SelectFaviconFramesForPixelSizesFromPNGs(png_data,
+                                                  desired_pixel_sizes);
+}
+
+gfx::Image SelectFaviconFramesForPixelSizesFromPNGs(
+    const std::vector<favicon_base::FaviconRawBitmapResult>& png_data,
+    const std::map<int, float>& desired_pixel_sizes) {
   // Create image reps for as many scales as possible without resizing
   // the bitmap data or decoding it. FaviconHandler stores already resized
   // favicons into history so no additional resizing should be needed in the
@@ -184,22 +197,12 @@ gfx::Image SelectFaviconFramesFromPNGs(
   //   significant performance hit if a user has many bookmarks.
   // TODO(pkotwicz): Move the decoding off the UI thread.
   std::vector<gfx::ImagePNGRep> png_reps =
-      SelectFaviconFramesFromPNGsWithoutResizing(
-          png_data, favicon_scales, favicon_size);
-
-  // SelectFaviconFramesFromPNGsWithoutResizing() should have selected the
-  // largest favicon if |favicon_size| == 0.
-  if (favicon_size == 0)
-    return gfx::Image(png_reps);
+      SelectFaviconFramesFromPNGsWithoutResizing(png_data, desired_pixel_sizes);
 
-  std::vector<float> favicon_scales_to_generate = favicon_scales;
+  std::map<int, float> favicon_scales_to_generate = desired_pixel_sizes;
   for (size_t i = 0; i < png_reps.size(); ++i) {
-    std::vector<float>::iterator iter = std::find(
-        favicon_scales_to_generate.begin(),
-        favicon_scales_to_generate.end(),
-        png_reps[i].scale);
-    if (iter != favicon_scales_to_generate.end())
-      favicon_scales_to_generate.erase(iter);
+    favicon_scales_to_generate.erase(
+        favicon_scales_to_generate.find(png_reps[i].Size().width()));
   }
 
   if (favicon_scales_to_generate.empty())
@@ -222,10 +225,9 @@ gfx::Image SelectFaviconFramesFromPNGs(
     return gfx::Image();
 
   gfx::ImageSkia resized_image_skia;
-  for (size_t i = 0; i < favicon_scales_to_generate.size(); ++i) {
-    float scale = favicon_scales_to_generate[i];
-    int desired_size_in_pixel =
-        static_cast<int>(std::ceil(favicon_size * scale));
+  for (const auto& scale_to_generate : favicon_scales_to_generate) {
+    float scale = scale_to_generate.second;
+    int desired_size_in_pixel = scale_to_generate.first;
     SkBitmap bitmap =
         ResizeBitmapByDownsamplingIfPossible(bitmaps, desired_size_in_pixel);
     resized_image_skia.AddRepresentation(gfx::ImageSkiaRep(bitmap, scale));