Fix chrome.downloads.getFileIcon for hi-dpi and clarify docs.

chrome/browser/extensions/api/downloads/downloads_api.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/extensions/api/downloads/downloads_api.h"
 
 #include <algorithm>
 #include <cctype>
 #include <iterator>
 #include <set>
@@ skipping 46 matching lines @@
 #include "components/web_modal/web_contents_modal_dialog_manager.h"
 #include "content/public/browser/download_interrupt_reasons.h"
 #include "content/public/browser/download_item.h"
 #include "content/public/browser/download_save_info.h"
 #include "content/public/browser/download_url_parameters.h"
 #include "content/public/browser/notification_details.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/notification_source.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/render_view_host.h"
+#include "content/public/browser/render_widget_host_view.h"
 #include "content/public/browser/resource_context.h"
 #include "content/public/browser/resource_dispatcher_host.h"
 #include "content/public/browser/web_contents.h"
-#include "content/public/browser/web_contents.h"
-#include "content/public/browser/web_contents_view.h"
 #include "content/public/browser/web_contents_view.h"
 #include "extensions/browser/event_router.h"
 #include "extensions/common/extension.h"
 #include "extensions/common/permissions/permissions_data.h"
 #include "net/base/load_flags.h"
 #include "net/base/net_util.h"
 #include "net/http/http_util.h"
 #include "net/url_request/url_request.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "ui/base/webui/web_ui_util.h"
+#include "ui/gfx/image/image_skia.h"
 
 using content::BrowserContext;
 using content::BrowserThread;
 using content::DownloadItem;
 using content::DownloadManager;
 
 namespace download_extension_errors {
 
 const char kEmptyFile[] = "Filename not yet determined";
 const char kFileAlreadyDeleted[] = "Download file already deleted";
@@ skipping 202 matching lines @@
   return scoped_ptr<base::DictionaryValue>(json);
 }
 
 class DownloadFileIconExtractorImpl : public DownloadFileIconExtractor {
  public:
   DownloadFileIconExtractorImpl() {}
 
   virtual ~DownloadFileIconExtractorImpl() {}
 
   virtual bool ExtractIconURLForPath(const base::FilePath& path,
+                                     float scale,
                                      IconLoader::IconSize icon_size,
                                      IconURLCallback callback) OVERRIDE;
  private:
   void OnIconLoadComplete(gfx::Image* icon);
 
   CancelableTaskTracker cancelable_task_tracker_;
+  float scale_;
   IconURLCallback callback_;
 };
 
 bool DownloadFileIconExtractorImpl::ExtractIconURLForPath(
     const base::FilePath& path,
+    float scale,
     IconLoader::IconSize icon_size,
     IconURLCallback callback) {
+  scale_ = scale;
   callback_ = callback;
   IconManager* im = g_browser_process->icon_manager();
   // The contents of the file at |path| may have changed since a previous
   // request, in which case the associated icon may also have changed.
   // Therefore, always call LoadIcon instead of attempting a LookupIcon.
   im->LoadIcon(path,
                icon_size,
                base::Bind(&DownloadFileIconExtractorImpl::OnIconLoadComplete,

[pkotwicz, 2014/01/15 02:33:37]

Would it be possible to pass |scale| as a parameter to OnIconLoadComplete() and
avoid the member variable?

[benjhayden, 2014/01/15 23:58:20]

Done.

                           base::Unretained(this)),
                &cancelable_task_tracker_);
   return true;
 }
 
 void DownloadFileIconExtractorImpl::OnIconLoadComplete(gfx::Image* icon) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  std::string url;
-  if (icon)
-    url = webui::GetBitmapDataUrl(icon->AsBitmap());
-  callback_.Run(url);
+  callback_.Run(!icon ? std::string() : webui::GetBitmapDataUrl(
+      icon->ToImageSkia()->GetRepresentation(scale_).sk_bitmap()));
 }
 
 IconLoader::IconSize IconLoaderSizeFromPixelSize(int pixel_size) {
   switch (pixel_size) {
     case 16: return IconLoader::SMALL;
     case 32: return IconLoader::NORMAL;
     default:
       NOTREACHED();
       return IconLoader::NORMAL;
   }
@@ skipping 1145 matching lines @@
       GetDownload(GetProfile(), include_incognito(), params->download_id);
   if (InvalidId(download_item, &error_) ||
       Fault(download_item->GetTargetFilePath().empty(),
             errors::kEmptyFile, &error_))
     return false;
   // In-progress downloads return the intermediate filename for GetFullPath()
   // which doesn't have the final extension. Therefore a good file icon can't be
   // found, so use GetTargetFilePath() instead.
   DCHECK(icon_extractor_.get());
   DCHECK(icon_size == 16 || icon_size == 32);
+  float scale = 1.0;
+  content::WebContents* web_contents =
+      dispatcher()->delegate()->GetVisibleWebContents();
+  if (web_contents) {
+    scale = ui::GetImageScale(ui::GetScaleFactorForNativeView(
+        web_contents->GetRenderWidgetHostView()->GetNativeView()));
+  }
   EXTENSION_FUNCTION_VALIDATE(icon_extractor_->ExtractIconURLForPath(
       download_item->GetTargetFilePath(),
+      scale,
       IconLoaderSizeFromPixelSize(icon_size),
       base::Bind(&DownloadsGetFileIconFunction::OnIconURLExtracted, this)));
   return true;
 }
 
 void DownloadsGetFileIconFunction::OnIconURLExtracted(const std::string& url) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   if (Fault(url.empty(), errors::kIconNotFound, &error_)) {
     SendResponse(false);
     return;
@@ skipping 391 matching lines @@
       extensions::UnloadedExtensionInfo* unloaded =
           content::Details<extensions::UnloadedExtensionInfo>(details).ptr();
       std::set<const extensions::Extension*>::iterator iter =
         shelf_disabling_extensions_.find(unloaded->extension);
       if (iter != shelf_disabling_extensions_.end())
         shelf_disabling_extensions_.erase(iter);
       break;
     }
   }
 }