Expose thumbnails of pages to iOS share extensions.

ios/chrome/browser/ui/activity_services/share_to_data.mm

Index: ios/chrome/browser/ui/activity_services/share_to_data.mm
diff --git a/ios/chrome/browser/ui/activity_services/share_to_data.mm b/ios/chrome/browser/ui/activity_services/share_to_data.mm
index 40018418250c8ae64248d14381fe36cf3005777c..5ea3b13e7773a5500716c200286c4ee2c7535df2 100644
--- a/ios/chrome/browser/ui/activity_services/share_to_data.mm
+++ b/ios/chrome/browser/ui/activity_services/share_to_data.mm
@@ -38,6 +38,7 @@
 
 @synthesize title = title_;
 @synthesize image = image_;
+@synthesize thumbnailGenerator = thumbnailGenerator_;
 @synthesize isOriginalTitle = isOriginalTitle_;
 @synthesize isPagePrintable = isPagePrintable_;
 
@@ -47,9 +48,10 @@
 }
 
 - (id)initWithURL:(const GURL&)url
-              title:(NSString*)title
-    isOriginalTitle:(BOOL)isOriginalTitle
-    isPagePrintable:(BOOL)isPagePrintable {
+                 title:(NSString*)title
+       isOriginalTitle:(BOOL)isOriginalTitle
+       isPagePrintable:(BOOL)isPagePrintable
+    thumbnailGenerator:(ThumbnailGeneratorBlock)thumbnailGenerator {
   DCHECK(url.is_valid());
   DCHECK(title);
   self = [super init];
@@ -58,6 +60,7 @@
     self.title = title;
     self.isOriginalTitle = isOriginalTitle;
     self.isPagePrintable = isPagePrintable;
+    self.thumbnailGenerator = thumbnailGenerator;
   }
   return self;
 }
@@ -71,24 +74,23 @@
 }
 
 - (BOOL)isEqual:(id)object {
+  // Used for testing.
   if (![object isMemberOfClass:self.class])
     return NO;
   DCHECK(self.url.is_valid());
   DCHECK(self.title);
   ShareToData* other = (ShareToData*)object;
+  CGSize size = CGSizeMake(40, 40);

[Olivier, 2017/01/24 16:54:05]

Add comment.
Block are equal if they give the same thumbnail.

[jif, 2017/01/25 15:17:29]

Ack.
I moved the code which makes this comment obsolete I think.

+  NSData* thumbnailData =
+      UIImagePNGRepresentation(self.thumbnailGenerator(size));
+  NSData* otherThumbnailData =
+      UIImagePNGRepresentation(other.thumbnailGenerator(size));
+  BOOL thumbnailDataIsEqual = thumbnailData == otherThumbnailData ||

[Olivier, 2017/01/24 16:54:05]

I don't think I see anywhere in tests where this can be false (you always have a
single snapshot in tests).
Is this ever effectively used?

[jif, 2017/01/25 15:17:29]

Done.
The bitmap comparison is used in the bvc_unittest.mm.

+                              [thumbnailData isEqual:otherThumbnailData];
   return self.url == other.url && [self.title isEqual:other.title] &&
          self.image == other.image &&
-         self.isOriginalTitle == other.isOriginalTitle;
-}
-
-- (NSUInteger)hash {
-  DCHECK(self.url.is_valid());
-  DCHECK(self.title);
-  const NSUInteger kPrime = 31;
-  NSString* urlString = base::SysUTF8ToNSString(self.url.spec());
-  return kPrime * kPrime * kPrime * urlString.hash +
-         kPrime * kPrime * self.title.hash + kPrime * self.image.hash +
-         (self.isOriginalTitle ? 0 : 1);
+         self.isOriginalTitle == other.isOriginalTitle &&
+         self.isPagePrintable == other.isPagePrintable && thumbnailDataIsEqual;
 }
 
 @end