arc: Fix Default icon issue when cached icon file is corrupted.

chrome/browser/ui/app_list/arc/arc_app_icon.cc

Index: chrome/browser/ui/app_list/arc/arc_app_icon.cc
diff --git a/chrome/browser/ui/app_list/arc/arc_app_icon.cc b/chrome/browser/ui/app_list/arc/arc_app_icon.cc
index f888755d4ab4f6cd8d233f51729d7ab10447a2b6..df5d812b2e6fdb5718e47572546f7c140103ebea 100644
--- a/chrome/browser/ui/app_list/arc/arc_app_icon.cc
+++ b/chrome/browser/ui/app_list/arc/arc_app_icon.cc
@@ -172,6 +172,7 @@ class ArcAppIcon::DecodeRequest : public ImageDecoder::ImageRequest {
   // ImageDecoder::ImageRequest
   void OnImageDecoded(const SkBitmap& bitmap) override;
   void OnDecodeImageFailed() override;
+
  private:
   base::WeakPtr<ArcAppIcon> host_;
   int dimension_;
@@ -206,6 +207,8 @@ void ArcAppIcon::DecodeRequest::OnImageDecoded(const SkBitmap& bitmap) {
     VLOG(2) << "Decoded ARC icon has unexpected dimension "
             << bitmap.width() << "x" << bitmap.height() << ". Expected "
             << expected_dim << "x" << ".";
+
+    host_->MaybeRequestIcon(scale_factor_);
     host_->DiscardDecodeRequest(this);
     return;
   }
@@ -214,7 +217,6 @@ void ArcAppIcon::DecodeRequest::OnImageDecoded(const SkBitmap& bitmap) {
   image_skia.AddRepresentation(gfx::ImageSkiaRep(
       bitmap,
       ui::GetScaleForScaleFactor(scale_factor_)));
-
   host_->Update(&image_skia);
   host_->DiscardDecodeRequest(this);
 }
@@ -225,6 +227,7 @@ void ArcAppIcon::DecodeRequest::OnDecodeImageFailed() {
   if (!host_)
     return;
 
+  host_->MaybeRequestIcon(scale_factor_);
   host_->DiscardDecodeRequest(this);
 }
 
@@ -270,11 +273,15 @@ void ArcAppIcon::LoadForScaleFactor(ui::ScaleFactor scale_factor) {
       base::Bind(&ArcAppIcon::OnIconRead, weak_ptr_factory_.GetWeakPtr()));
 }
 
-void ArcAppIcon::RequestIcon(ui::ScaleFactor scale_factor) {
+void ArcAppIcon::MaybeRequestIcon(ui::ScaleFactor scale_factor) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   ArcAppListPrefs* prefs = ArcAppListPrefs::Get(context_);
   DCHECK(prefs);
 
+  // Request for Icon has been recorded. Don't resend same request within same
+  // user session.
+  if (prefs->IsIconRequestRecorded(app_id_, scale_factor))

[khmel, 2017/03/15 01:16:55]

Could you please move this logic into prefs. It would be nice to have
centralized logic that handles request there.

[lgcheng, 2017/03/15 19:59:31]

Done.

+    return;
   // ArcAppListPrefs notifies ArcAppModelBuilder via Observer when icon is ready
   // and ArcAppModelBuilder refreshes the icon of the corresponding item by
   // calling LoadScaleFactor.
@@ -317,8 +324,15 @@ void ArcAppIcon::OnIconRead(
     std::unique_ptr<ArcAppIcon::ReadResult> read_result) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 
-  if (read_result->request_to_install)
-    RequestIcon(read_result->scale_factor);
+  // When unsafe_icon_data is empty, there are four senarios.
+  // 1. Default app icon path is non valid. In this case, request_to_install is
+  // true.
+  // 2. Fail to read default icon file. In this case request_to_install is true.
+  // 3. Default icon file is empty. In this case request_to_install is true.
+  // 4. Icon file for app_id_ is empty. This indicates a file corruption of some
+  // sort of issue. We should try to request app icon.
+  if (read_result->request_to_install || read_result->unsafe_icon_data.empty())

[khmel, 2017/03/15 01:16:55]

Could you please move read_result->unsafe_icon_data.empty() check to place where
it is actually used?

[lgcheng, 2017/03/15 19:59:31]

Done.

+    MaybeRequestIcon(read_result->scale_factor);
 
   if (!read_result->unsafe_icon_data.empty()) {
     decode_requests_.push_back(base::MakeUnique<DecodeRequest>(