Reduce the use of ui::ScaleFactor in webui/favicon

chrome/browser/ui/webui/favicon_source.cc

 // Copyright (c) 2012 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 "chrome/browser/ui/webui/favicon_source.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/strings/string_number_conversions.h"
 #include "chrome/browser/favicon/favicon_service_factory.h"
@@ skipping 61 matching lines @@
 
   chrome::ParsedFaviconPath parsed;
   bool success = chrome::ParseFaviconPath(path, icon_types_, &parsed);
   if (!success) {
     SendDefaultResponse(callback);
     return;
   }
 
   GURL url(parsed.url);
 
+  ui::ScaleFactor scale_factor =
+      ui::GetSupportedScaleFactor(parsed.scale_factor);

[pkotwicz, 2014/05/20 03:31:19]

It is really confusing keeping track what it a float and what is a
ui::ScaleFactor now.

At one point, I did not want any floats to be named |scale_factor|.
Can you promise that when you rename ui::ScaleFactor to ui::ResourceScaleFactor
that you will rename all places which use ui::ResourceScaleFactor to something
unique to avoid confusion?

[oshima, 2014/05/20 18:23:28]

These will be renamed either

device_scale_factor (float) or

ui::ResourceScaleFactor/resource_scale_factor

   if (parsed.is_icon_url) {
     // TODO(michaelbai): Change GetRawFavicon to support combination of
     // IconType.
     favicon_service->GetRawFavicon(
         url,
         favicon_base::FAVICON,
         parsed.size_in_dip,
-        parsed.scale_factor,
+        scale_factor,
         base::Bind(&FaviconSource::OnFaviconDataAvailable,
                    base::Unretained(this),
                    IconRequest(
-                       callback, url, parsed.size_in_dip, parsed.scale_factor)),
+                       callback, url, parsed.size_in_dip, scale_factor)),
         &cancelable_task_tracker_);
   } else {
     // Intercept requests for prepopulated pages.
     for (size_t i = 0; i < arraysize(history::kPrepopulatedPages); i++) {
       if (url.spec() ==
           l10n_util::GetStringUTF8(history::kPrepopulatedPages[i].url_id)) {
         callback.Run(
             ResourceBundle::GetSharedInstance().LoadDataResourceBytesForScale(
                 history::kPrepopulatedPages[i].favicon_id,
-                parsed.scale_factor));
+                scale_factor));
         return;
       }
     }
 
     favicon_service->GetRawFaviconForURL(
         FaviconService::FaviconForURLParams(url, icon_types_,
                                             parsed.size_in_dip),
-        parsed.scale_factor,
+        scale_factor,
         base::Bind(&FaviconSource::OnFaviconDataAvailable,
                    base::Unretained(this),
                    IconRequest(callback,
                                url,
                                parsed.size_in_dip,
-                               parsed.scale_factor)),
+                               scale_factor)),
         &cancelable_task_tracker_);
   }
 }
 
 std::string FaviconSource::GetMimeType(const std::string&) const {
   // We need to explicitly return a mime type, otherwise if the user tries to
   // drag the image they get no extension.
   return "image/png";
 }
 
@@ skipping 57 matching lines @@
       break;
     default:
       favicon_index = SIZE_16;
       resource_id = IDR_DEFAULT_FAVICON;
       break;
   }
   base::RefCountedMemory* default_favicon =
       default_favicons_[favicon_index].get();
 
   if (!default_favicon) {
-    ui::ScaleFactor scale_factor = icon_request.scale_factor;
     default_favicon = ResourceBundle::GetSharedInstance()
-        .LoadDataResourceBytesForScale(resource_id, scale_factor);
+        .LoadDataResourceBytesForScale(resource_id,
+                                       icon_request.scale_factor);
     default_favicons_[favicon_index] = default_favicon;
   }
 
   icon_request.callback.Run(default_favicon);
 }