Adopt SDAnimatedImage for `sd_imageFrameCount`

SDWebImage/Core/SDAnimatedImage.m

@@ -314,6 +314,10 @@ static CGFloat SDImageScaleFromPath(NSString *string) {
     return;
 }
 
+- (NSUInteger)sd_imageFrameCount {
+    return self.animatedImageFrameCount;
+}
+
 - (SDImageFormat)sd_imageFormat {
     return self.animatedImageFormat;
 }

SDWebImage/Core/UIImage+MemoryCacheCost.m

@@ -21,7 +21,7 @@ FOUNDATION_STATIC_INLINE NSUInteger SDMemoryCacheCostForImage(UIImage *image) {
     frameCount = 1;
 #elif SD_UIKIT || SD_WATCH
     // Filter the same frame in `_UIAnimatedImage`.
-    frameCount = image.images.count > 0 ? [NSSet setWithArray:image.images].count : 1;
+    frameCount = image.images.count > 1 ? [NSSet setWithArray:image.images].count : 1;
 #endif
     NSUInteger cost = bytesPerFrame * frameCount;
     return cost;

Tests/Tests/SDImageCoderTests.m

@@ -410,9 +410,7 @@ withLocalImageURL:(NSURL *)imageUrl
         UIImage *outputImage = [coder decodedImageWithData:outputImageData options:nil];
         expect(outputImage.size).to.equal(inputImage.size);
         expect(outputImage.scale).to.equal(inputImage.scale);
-#if SD_UIKIT
-        expect(outputImage.images.count).to.equal(inputImage.images.count);
-#endif
+        expect(outputImage.sd_imageLoopCount).to.equal(inputImage.sd_imageLoopCount);
         
         // check max pixel size encoding with scratch
         CGFloat maxWidth = 50;
@@ -429,9 +427,7 @@ withLocalImageURL:(NSURL *)imageUrl
         // Image/IO's thumbnail API does not always use round to preserve precision, we check ABS <= 1
         expect(ABS(outputMaxImage.size.width - maxPixelSize.width)).beLessThanOrEqualTo(1);
         expect(ABS(outputMaxImage.size.height - maxPixelSize.height)).beLessThanOrEqualTo(1);
-#if SD_UIKIT
-        expect(outputMaxImage.images.count).to.equal(inputImage.images.count);
-#endif
+        expect(outputMaxImage.sd_imageLoopCount).to.equal(inputImage.sd_imageLoopCount);
     }
 }