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

components/arc/test/fake_app_instance.h

 // Copyright 2015 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.
 
 #ifndef COMPONENTS_ARC_TEST_FAKE_APP_INSTANCE_H_
 #define COMPONENTS_ARC_TEST_FAKE_APP_INSTANCE_H_
 
 #include <map>
 #include <memory>
 #include <string>
@@ skipping 107 matching lines @@
   void SendAppAdded(const mojom::AppInfo& app);
   void SendPackageAppListRefreshed(const std::string& package_name,
                                    const std::vector<mojom::AppInfo>& apps);
   void SendTaskCreated(int32_t taskId,
                        const mojom::AppInfo& app,
                        const std::string& intent);
   void SendTaskDestroyed(int32_t taskId);
   bool GenerateAndSendIcon(const mojom::AppInfo& app,
                            mojom::ScaleFactor scale_factor,
                            std::string* png_data_as_string);
+  void GenerateAndSendBadIcon(const mojom::AppInfo& app,
+                              mojom::ScaleFactor scale_factor,
+                              std::string* png_data_as_string);

[Luis Héctor Chávez, 2017/03/15 20:28:52]

can you convert this to a std::vector<uint8_t>*? std::string seems like a bad
abstraction for binary data.

[lgcheng, 2017/03/15 22:05:34]

In fact the std::string* png_data_as_string is not need in the test I added. I
remove the last argument.
But for the existing functions,  base::ReadFileToString is used to read binary,
so I'd not touch std::string* png_data_as_string there. WDYT?

[Luis Héctor Chávez, 2017/03/15 22:49:50]

I see, the removal of this parameter sgtm.

The other usage is kind of unfortunate though :/ I think I'm begrudgingly fine
with leaving that one as-is since this is testing-only code.

   void SendInstallShortcut(const mojom::ShortcutInfo& shortcuts);
   void SendInstallShortcuts(const std::vector<mojom::ShortcutInfo>& shortcuts);
   void SetTaskInfo(int32_t task_id,
                    const std::string& package_name,
                    const std::string& activity);
   void SendRefreshPackageList(
       const std::vector<mojom::ArcPackageInfo>& packages);
   void SendPackageAdded(const mojom::ArcPackageInfo& package);
   void SendPackageUninstalled(const std::string& pacakge_name);
 
@@ skipping 39 matching lines @@
 
   bool GetFakeIcon(mojom::ScaleFactor scale_factor,
                    std::string* png_data_as_string);
 
   DISALLOW_COPY_AND_ASSIGN(FakeAppInstance);
 };
 
 }  // namespace arc
 
 #endif  // COMPONENTS_ARC_TEST_FAKE_APP_INSTANCE_H_