Implement safebrowsing download feedback service, enabled for dev & canary only.

chrome/browser/safe_browsing/download_protection_service.h

Index: chrome/browser/safe_browsing/download_protection_service.h
diff --git a/chrome/browser/safe_browsing/download_protection_service.h b/chrome/browser/safe_browsing/download_protection_service.h
index d7407b24cc9a9d34bf87e56e76d558b41e7724c7..045bb2fc27b9554be1f513f628c284b2d6bff8fe 100644
--- a/chrome/browser/safe_browsing/download_protection_service.h
+++ b/chrome/browser/safe_browsing/download_protection_service.h
@@ -33,6 +33,7 @@ class X509Certificate;
 }  // namespace net
 
 namespace safe_browsing {
+class DownloadFeedbackService;
 class SignatureUtil;
 
 // This class provides an asynchronous API to check whether a particular
@@ -100,6 +101,10 @@ class DownloadProtectionService {
     return download_request_timeout_ms_;
   }
 
+  DownloadFeedbackService* feedback_service() {
+    return feedback_service_.get();
+  }
+
  protected:
   // Enum to keep track why a particular download verdict was chosen.
   // This is used to keep some stats around.
@@ -186,6 +191,8 @@ class DownloadProtectionService {
 
   int64 download_request_timeout_ms_;
 
+  scoped_ptr<DownloadFeedbackService> feedback_service_;
+
   DISALLOW_COPY_AND_ASSIGN(DownloadProtectionService);
 };
 }  // namespace safe_browsing