Compressing .pak resources with new option: "type=GZIPPABLE_BINDATA"

ui/base/resource/resource_bundle.h

 // 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.
 
 #ifndef UI_BASE_RESOURCE_RESOURCE_BUNDLE_H_
 #define UI_BASE_RESOURCE_RESOURCE_BUNDLE_H_
 
 #include <stddef.h>
 
 #include <map>
@@ skipping 32 matching lines @@
 // such as theme graphics. Every resource is loaded only once.
 class UI_BASE_EXPORT ResourceBundle {
  public:
   // Legacy font size deltas. Consider these to be magic numbers. New code
   // should declare their own size delta constant using an identifier that
   // imparts some semantic meaning.
   static const int kSmallFontDelta = -1;
   static const int kMediumFontDelta = 3;
   static const int kLargeFontDelta = 8;
 
+  static constexpr const char* CUSTOM_GZIP_HEADER = "\xff\x1f\x8b";
+
   // Legacy font style mappings. TODO(tapted): Phase these out in favour of
   // client code providing their own constant with the desired font size delta.
   enum FontStyle {
     SmallFont,
     SmallBoldFont,
     BaseFont,
     BoldFont,
     MediumFont,
     MediumBoldFont,
     LargeFont,
@@ skipping 146 matching lines @@
   // Similar to GetImageNamed, but rather than loading the image in Skia format,
   // it will load in the native platform type. This can avoid conversion from
   // one image type to another. ResourceBundle owns the result.
   //
   // Note that if the same resource has already been loaded in GetImageNamed(),
   // gfx::Image will perform a conversion, rather than using the native image
   // loading code of ResourceBundle.
   gfx::Image& GetNativeImageNamed(int resource_id);
 
   // Loads the raw bytes of a scale independent data resource.
+  // Will perform gzip decompression on any resource which has
+  // ResourceBundle::CUSTOM_GZIP_HEADER as its first 3 bytes.

[agrieve, 2016/05/27 17:40:00]

nit: can you also add here that you can enable this via the compress="gzip" 

[smaier, 2016/05/27 17:48:47]

Done.

   base::RefCountedMemory* LoadDataResourceBytes(int resource_id) const;
 
   // Loads the raw bytes of a data resource nearest the scale factor
   // |scale_factor| into |bytes|, without doing any processing or
   // interpretation of the resource. Use ResourceHandle::SCALE_FACTOR_NONE
   // for scale independent image resources (such as wallpaper).
+  // Will perform gzip decompression on any resource which has
+  // ResourceBundle::CUSTOM_GZIP_HEADER as its first 3 bytes.
   // Returns NULL if we fail to read the resource.
   base::RefCountedMemory* LoadDataResourceBytesForScale(
       int resource_id,
       ScaleFactor scale_factor) const;
 
   // Return the contents of a scale independent resource in a
-  // StringPiece given the resource id
+  // StringPiece given the resource id.
+  // NOTE: CHECKs to ensure this is not called on a resource which has
+  // ResourceBundle::CUSTOM_GZIP_HEADER as its first 3 bytes.
   base::StringPiece GetRawDataResource(int resource_id) const;
 
   // Return the contents of a resource in a StringPiece given the resource id
   // nearest the scale factor |scale_factor|.
   // Use ResourceHandle::SCALE_FACTOR_NONE for scale independent image resources
   // (such as wallpaper).
+  // NOTE: CHECKs to ensure this is not called on a resource which has
+  // ResourceBundle::CUSTOM_GZIP_HEADER as its first 3 bytes.
   base::StringPiece GetRawDataResourceForScale(int resource_id,
                                                ScaleFactor scale_factor) const;
 
   // Get a localized string given a message id.  Returns an empty
   // string if the message_id is not found.
   base::string16 GetLocalizedString(int message_id);
 
   // Returns a font list derived from the platform-specific "Base" font list.
   // The result is always cached and exists for the lifetime of the process.
   const gfx::FontList& GetFontListWithDelta(
@@ skipping 127 matching lines @@
 
   // Fills the |bitmap| given the |resource_id| and |scale_factor|.
   // Returns false if the resource does not exist. This may fall back to
   // the data pack with SCALE_FACTOR_NONE, and when this happens,
   // |scale_factor| will be set to SCALE_FACTOR_100P.
   bool LoadBitmap(int resource_id,
                   ScaleFactor* scale_factor,
                   SkBitmap* bitmap,
                   bool* fell_back_to_1x) const;
 
+  // Loads the raw bytes of a data resource nearest the scale factor
+  // |scale_factor| into |bytes|, without doing any processing or
+  // interpretation of the resource. Use ResourceHandle::SCALE_FACTOR_NONE
+  // for scale independent image resources (such as wallpaper).
+  // Returns NULL if we fail to read the resource.
+  base::StringPiece DoGetRawDataResourceForScale(
+      int resource_id,
+      ScaleFactor scale_factor) const;
+
   // Returns true if missing scaled resources should be visually indicated when
   // drawing the fallback (e.g., by tinting the image).
   static bool ShouldHighlightMissingScaledResources();
 
   // Returns true if the data in |buf| is a PNG that has the special marker
   // added by GRIT that indicates that the image is actually 1x data.
   static bool PNGContainsFallbackMarker(const unsigned char* buf, size_t size);
 
   // A wrapper for PNGCodec::Decode that returns information about custom
   // chunks. For security reasons we can't alter PNGCodec to return this
@@ skipping 48 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(ResourceBundle);
 };
 
 }  // namespace ui
 
 // TODO(beng): Someday, maybe, get rid of this.
 using ui::ResourceBundle;
 
 #endif  // UI_BASE_RESOURCE_RESOURCE_BUNDLE_H_