Newspaper is both countable and uncountable. For example:
Did you read the newspaper today? -- here it's countable because it's referring to an individual news publication.
Wrap the broken glass in newspaper -- here it's uncountable because it's referring to a type of paper in general.
Chocolate is also both countable and uncountable. For example:
Life is like a box of chocolates, you never know what you're going to get -- here's it's countable, because it's referring to individual chocolate sweets, pieces of chocolate, or chocolate bars.
Would you like some chocolate? -- here it's uncountable, because it's referring to the food in general.