Skips the processing of images larger then 88x88 in favicons.

skia/ext/skia_utils_ios.mm

 // Copyright 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 "skia/ext/skia_utils_ios.h"
 
 #import <ImageIO/ImageIO.h>
 #import <UIKit/UIKit.h>
 
+#include "base/ios/ios_util.h"
 #include "base/logging.h"
 #include "base/mac/scoped_cftyperef.h"
+#include "base/macros.h"
 #include "third_party/skia/include/utils/mac/SkCGUtils.h"
 
+namespace {
+
+const uint8 kICOHeaderMagic[4] = {0x00, 0x00, 0x01, 0x00};
+
+// Returns whether the data encodes an ico image.
+bool EncodesIcoImage(NSData* image_data) {
+  if (image_data.length < arraysize(kICOHeaderMagic))
+    return false;
+  return memcmp(kICOHeaderMagic, image_data.bytes,
+                arraysize(kICOHeaderMagic)) == 0;
+}
+
+}  // namespace
+
 namespace gfx {
 
 SkBitmap CGImageToSkBitmap(CGImageRef image, CGSize size, bool is_opaque) {
   SkBitmap bitmap;
   if (!image)
     return bitmap;
 
   if (!bitmap.tryAllocN32Pixels(size.width, size.height, is_opaque))
     return bitmap;
 
@@ skipping 43 matching lines @@
       SkCreateCGImageRefWithColorspace(skia_bitmap, color_space));
 
   // Now convert to UIImage.
   return [UIImage imageWithCGImage:cg_image.get()
                              scale:scale
                        orientation:UIImageOrientationUp];
 }
 
 std::vector<SkBitmap> ImageDataToSkBitmaps(NSData* image_data) {
   DCHECK(image_data);
+
+  // On iOS 8.1.1 |CGContextDrawImage| crashes when processing images included
+  // in .ico files that are larger then 88x88 (http://crbug.com/435068).

[Justin Novosad, 2015/02/19 16:10:44]

then -> than

[sdefresne, 2015/02/19 16:46:02]

Done.

+  bool skip_images_larger_than_88x88 =
+      base::ios::IsRunningOnOrLater(8, 1, 1) && EncodesIcoImage(image_data);
+
   base::ScopedCFTypeRef<CFDictionaryRef> empty_dictionary(
       CFDictionaryCreate(NULL, NULL, NULL, 0, NULL, NULL));
   std::vector<SkBitmap> frames;
 
   base::ScopedCFTypeRef<CGImageSourceRef> source(
       CGImageSourceCreateWithData((CFDataRef)image_data, empty_dictionary));
 
   size_t count = CGImageSourceGetCount(source);
   for (size_t index = 0; index < count; ++index) {
     base::ScopedCFTypeRef<CGImageRef> cg_image(
         CGImageSourceCreateImageAtIndex(source, index, empty_dictionary));
 
     CGSize size = CGSizeMake(CGImageGetWidth(cg_image),
                              CGImageGetHeight(cg_image));
-    const SkBitmap bitmap = CGImageToSkBitmap(cg_image, size, false);
-    if (!bitmap.empty())
-      frames.push_back(bitmap);
+    if (!skip_images_larger_than_88x88 ||
+        (size.width < 88 && size.height < 88)) {

[Justin Novosad, 2015/02/19 16:10:44]

Shouldn't the conditions be '<=' instead of '<'?  If not, the your comments and
variable name are wrong (skip_images_88x88_or_larger?)

[sdefresne, 2015/02/19 16:46:02]

That's correct. Changed to use <=.

+      const SkBitmap bitmap = CGImageToSkBitmap(cg_image, size, false);
+      if (!bitmap.empty())
+        frames.push_back(bitmap);
+    }
   }
 
   DLOG_IF(WARNING, frames.size() != count) << "Only decoded " << frames.size()
       << " frames for " << count << " expected.";
   return frames;
 }
 
 }  // namespace gfx