Remove unused NotificationImageReporter-related messages from csd.proto

Bug: 837707
Change-Id: Ie6fd9d6587e248ce0467c92b95a084c789d66e75
Reviewed-on: https://chromium-review.googlesource.com/c/1435218
Commit-Queue: Varun Khaneja <vakh@chromium.org>
Reviewed-by: Varun Khaneja <vakh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#625840}

components/safe_browsing/proto/csd.proto

@@ -1290,36 +1290,6 @@ message HTMLElement {
   repeated Attribute attribute = 6;
 }
 
-// Canonical representation of raster image data.
-message ImageData {
-  // Image bitmap, after downscaling to <= 512x512.
-  optional bytes data = 1;
-
-  // Encoding scheme for the bitmap.
-  optional string mime_type = 2;
-
-  message Dimensions {
-    optional int32 width = 1;
-    optional int32 height = 2;
-  }
-
-  // Dimensions of the image stored in |data|.
-  optional Dimensions dimensions = 3;
-  optional Dimensions original_dimensions = 4;  // iff downscaled
-}
-
-// Reporting protobuf for an image served as part of a browser notification.
-// There is no response (an empty body) to this request.
-message NotificationImageReportRequest {
-  optional string notification_origin = 1;  // Src-origin of the notification.
-  optional ImageData image = 2;             // The bitmap of the image.
-
-  // Note that the image URL is deliberately omitted as it would be untrusted,
-  // since the notification image fetch may be intercepted by a Service Worker
-  // (even if the image URL is cross-origin). Otherwise a website could mislead
-  // Safe Browsing into associating phishing image bitmaps with safe image URLs.
-}
-
 // Protobuf for Chrome extension webstore install request.
 message ExtensionWebStoreInstallRequest {
   // If we can find the complete referrer chain, this field will contain URL