Support server categories in NTPSnippetsService.

components/ntp_snippets/ntp_snippets_database.h

Index: components/ntp_snippets/ntp_snippets_database.h
diff --git a/components/ntp_snippets/ntp_snippets_database.h b/components/ntp_snippets/ntp_snippets_database.h
index 983166235f0ca70265f66149e3ae6c9b6aa842d5..2c76a45e44ed6b8bd838e66b2f2bb71e7359f3ef 100644
--- a/components/ntp_snippets/ntp_snippets_database.h
+++ b/components/ntp_snippets/ntp_snippets_database.h
@@ -29,7 +29,7 @@ class SnippetProto;
 class NTPSnippetsDatabase {
  public:
   using SnippetsCallback = base::Callback<void(NTPSnippet::PtrVector)>;
-  using SnippetImageCallback = base::Callback<void(std::string)>;
+  using SnippetImageCallback = base::Callback<void(std::string suggestion_id)>;
 
   NTPSnippetsDatabase(
       const base::FilePath& database_dir,
@@ -63,14 +63,15 @@ class NTPSnippetsDatabase {
 
   // Loads the image data for the snippet with the given ID and passes it to
   // |callback|. Passes an empty string if not found.
-  void LoadImage(const std::string& snippet_id,
+  void LoadImage(const std::string& suggestion_id,
                  const SnippetImageCallback& callback);
 
   // Adds or updates the image data for the given snippet ID.
-  void SaveImage(const std::string& snippet_id, const std::string& image_data);
+  void SaveImage(const std::string& suggestion_id,
+                 const std::string& image_data);
 
   // Deletes the image data for the given snippet ID.
-  void DeleteImage(const std::string& snippet_id);
+  void DeleteImage(const std::string& suggestion_id);
 
  private:
   friend class NTPSnippetsDatabaseTest;
@@ -104,7 +105,7 @@ class NTPSnippetsDatabase {
   void DeleteSnippetsImpl(
       std::unique_ptr<std::vector<std::string>> keys_to_remove);
 
-  void LoadImageImpl(const std::string& snippet_id,
+  void LoadImageImpl(const std::string& suggestion_id,
                      const SnippetImageCallback& callback);
   void DeleteImagesImpl(
       std::unique_ptr<std::vector<std::string>> keys_to_remove);