Add new ResourceBundle::Delegate interface.

ui/base/resource/resource_bundle.h

Index: ui/base/resource/resource_bundle.h
===================================================================
--- ui/base/resource/resource_bundle.h	(revision 135347)
+++ ui/base/resource/resource_bundle.h	(working copy)
@@ -19,6 +19,8 @@
 #include "base/string16.h"
 #include "base/string_piece.h"
 #include "ui/base/ui_export.h"
+#include "ui/gfx/font.h"
+#include "ui/gfx/image/image.h"
 #include "ui/gfx/native_widget_types.h"
 
 class SkBitmap;
@@ -28,11 +30,6 @@
 class RefCountedStaticMemory;
 }
 
-namespace gfx {
-class Font;
-class Image;
-}
-
 namespace ui {
 
 class ResourceHandle;
@@ -63,12 +60,60 @@
     RTL_DISABLED,
   };
 
-  // Initialize the ResourceBundle for this process.  Returns the language
-  // selected.
+  // Delegate class that allows interception of pack file loading and resource
+  // requests. The methods of this class may be called on multiple threads.
+  class Delegate {
+   public:
+    // Called before a resource pack file is loaded. Return the full path for
+    // the pack file to continue loading or an empty value to cancel loading.
+    // |pack_path| will contain the complete default path for the pack file if
+    // known or just the pack file name otherwise.
+    virtual FilePath GetPathForResourcePack(const FilePath& pack_path,
+                                            float scale_factor) = 0;
+
+    // Called before a locale pack file is loaded. Return the full path for
+    // the pack file to continue loading or an empty value to cancel loading.
+    // |pack_path| will contain the complete default path for the pack file if
+    // known or just the pack file name otherwise.
+    virtual FilePath GetPathForLocalePack(const FilePath& pack_path,
+                                          const std::string& locale) = 0;
+
+    // Return an image resource or an empty value to attempt retrieval of the
+    // default resource.
+    virtual gfx::Image GetImageNamed(int resource_id) = 0;
+
+    // Return an image resource or an empty value to attempt retrieval of the
+    // default resource.
+    virtual gfx::Image GetNativeImageNamed(int resource_id, ImageRTL rtl) = 0;
+
+    // Return a static memory resource or NULL to attempt retrieval of the
+    // default resource.
+    virtual base::RefCountedStaticMemory* LoadDataResourceBytes(
+        int resource_id) = 0;
+
+    // Retrieve a raw data resource. Return true if a resource was provided or
+    // false to attempt retrieval of the default resource.
+    virtual bool GetRawDataResource(int resource_id,
+                                    base::StringPiece* value) = 0;
+
+    // Retrieve a localized string. Return true if a string was provided or
+    // false to attempt retrieval of the default string.
+    virtual bool GetLocalizedString(int message_id, string16* value) = 0;
+
+    // Return a font resource or NULL to attempt retrieval of the default
+    // resource.
+    virtual scoped_ptr<gfx::Font> GetFont(FontStyle style) = 0;
+
+   protected:
+    virtual ~Delegate() {}
+  };
+
+  // Initialize the ResourceBundle for this process. Does not take ownership of
+  // the |delegate| value. Returns the language selected.
   // NOTE: Mac ignores this and always loads up resources for the language
   // defined by the Cocoa UI (i.e., NSBundle does the language work).
   static std::string InitSharedInstanceWithLocale(
-      const std::string& pref_locale);
+      const std::string& pref_locale, Delegate* delegate);
 
   // Initialize the ResourceBundle using given data pack path for testing.
   static void InitSharedInstanceWithPakFile(const FilePath& path);
@@ -83,11 +128,13 @@
   static ResourceBundle& GetSharedInstance();
 
   // Check if the .pak for the given locale exists.
-  static bool LocaleDataPakExists(const std::string& locale);
+  bool LocaleDataPakExists(const std::string& locale);
 
-  // Registers additional data pack files with the global ResourceBundle.  When
+  // Registers additional data pack files with this ResourceBundle.  When
   // looking for a DataResource, we will search these files after searching the
-  // main module. |scale_factor| is the scale of images in this resource pak
+  // main module. |path| should be the complete path to the pack file if known
+  // or just the pack file name otherwise (the delegate may optionally override
+  // this value). |scale_factor| is the scale of images in this resource pak
   // relative to the images in the 1x resource pak. This method is not thread
   // safe! You should call it immediately after calling InitSharedInstance.
   void AddDataPack(const FilePath& path, float scale_factor);
@@ -149,10 +196,19 @@
   void OverrideLocalePakForTest(const FilePath& pak_path);
 
  private:
+  FRIEND_TEST_ALL_PREFIXES(ResourceBundle, DelegateGetPathForResourcePack);
+  FRIEND_TEST_ALL_PREFIXES(ResourceBundle, DelegateGetPathForLocalePack);
+  FRIEND_TEST_ALL_PREFIXES(ResourceBundle, DelegateGetImageNamed);
+  FRIEND_TEST_ALL_PREFIXES(ResourceBundle, DelegateGetNativeImageNamed);
+  FRIEND_TEST_ALL_PREFIXES(ResourceBundle, DelegateLoadDataResourceBytes);
+  FRIEND_TEST_ALL_PREFIXES(ResourceBundle, DelegateGetRawDataResource);
+  FRIEND_TEST_ALL_PREFIXES(ResourceBundle, DelegateGetLocalizedString);
+  FRIEND_TEST_ALL_PREFIXES(ResourceBundle, DelegateGetFont);
   FRIEND_TEST_ALL_PREFIXES(ResourceBundle, LoadDataResourceBytes);
+  FRIEND_TEST_ALL_PREFIXES(ResourceBundle, LocaleDataPakExists);
 
   // Ctor/dtor are private, since we're a singleton.
-  ResourceBundle();
+  explicit ResourceBundle(Delegate* delegate);
   ~ResourceBundle();
 
   // Free skia_images_.
@@ -177,7 +233,7 @@
 
   // Returns the full pathname of the locale file to load.  May return an empty
   // string if no locale data files are found.
-  static FilePath GetLocaleFilePath(const std::string& app_locale);
+  FilePath GetLocaleFilePath(const std::string& app_locale);
 
   // Creates and returns a new SkBitmap given the data file to look in and the
   // resource id.  It's up to the caller to free the returned bitmap when
@@ -186,10 +242,14 @@
 
   // Returns an empty image for when a resource cannot be loaded. This is a
   // bright red bitmap.
-  gfx::Image* GetEmptyImage();
+  gfx::Image& GetEmptyImage();
 
   const FilePath& GetOverriddenPakPath();
 
+  // This pointer is guaranteed to outlive the ResourceBundle instance and may
+  // be NULL.
+  Delegate* delegate_;
+
   // Protects |images_| and font-related members.
   scoped_ptr<base::Lock> images_and_fonts_lock_;
 
@@ -202,9 +262,11 @@
 
   // Cached images. The ResourceBundle caches all retrieved images and keeps
   // ownership of the pointers.
-  typedef std::map<int, gfx::Image*> ImageMap;
+  typedef std::map<int, gfx::Image> ImageMap;
   ImageMap images_;
 
+  gfx::Image empty_image_;
+
   // The various fonts used. Cached to avoid repeated GDI creation/destruction.
   scoped_ptr<gfx::Font> base_font_;
   scoped_ptr<gfx::Font> bold_font_;