Expose thumbnails of pages to iOS share extensions.

ui/base/test/ios/ui_image_test_utils.mm

+// Copyright 2017 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 "ui/base/test/ios/ui_image_test_utils.h"
+
+#include "base/mac/scoped_cftyperef.h"
+
+namespace ui {
+namespace test {
+namespace uiimage_utils {
+
+UIImage* UIImageWithSizeAndSolidColor(CGSize const& size, UIColor* color) {
+  UIGraphicsBeginImageContext(size);
+  CGContextRef context = UIGraphicsGetCurrentContext();
+  CGContextSetFillColorWithColor(context, [color CGColor]);
+  CGContextFillRect(context, CGRectMake(0, 0, size.width, size.height));
+  UIImage* image_with_solid_color = UIGraphicsGetImageFromCurrentImageContext();
+  UIGraphicsEndImageContext();
+  return image_with_solid_color;
+}
+
+bool UIImagesAreEqual(UIImage* image_1, UIImage* image_2) {
+  if (image_1 == image_2)
+    return true;
+
+  if (!CGSizeEqualToSize(image_1.size, image_2.size))
+    return false;
+
+  bool images_are_equal = false;
+
+  base::ScopedCFTypeRef<CFDataRef> data_ref_1(
+      CGDataProviderCopyData(CGImageGetDataProvider(image_1.CGImage)));
+  base::ScopedCFTypeRef<CFDataRef> data_ref_2(
+      CGDataProviderCopyData(CGImageGetDataProvider(image_2.CGImage)));
+  CFIndex length_1 = CFDataGetLength(data_ref_1);
+  CFIndex length_2 = CFDataGetLength(data_ref_2);
+  if (length_1 == length_2) {

[sdefresne, 2017/01/30 16:56:20]

Can you use early return here too?

  if (length_1 != length_2)
    return false;

  const UInt8* ptr_1 = CFDataGetBytePtr(data_ref_1);
  const UInt8* ptr_2 = CFDataGetBytePtr(data_ref_2);
  return memcmp(ptr_1, ptr_2, length_1) == 0;

[jif, 2017/02/03 10:54:49]

Done.

+    const UInt8* ptr_1 = CFDataGetBytePtr(data_ref_1);
+    const UInt8* ptr_2 = CFDataGetBytePtr(data_ref_2);
+
+    // memcmp returns 0 if length is 0.
+    if (memcmp(ptr_1, ptr_2, length_1) == 0)
+      images_are_equal = true;
+  }
+
+  return images_are_equal;
+}
+
+}  // namespace uiimage_utils
+}  // namespace test
+}  // namespace ui