v4_update_protocol_manager: Basic implementation with TODOs

components/safe_browsing_db/v4_protocol_manager_util.h

Index: components/safe_browsing_db/v4_protocol_manager_util.h
diff --git a/components/safe_browsing_db/v4_protocol_manager_util.h b/components/safe_browsing_db/v4_protocol_manager_util.h
index f4665f00587fc979ddbab8bb19c4530b87cd4287..983df4255445c534b36cd297516e0a8ea7fa06bb 100644
--- a/components/safe_browsing_db/v4_protocol_manager_util.h
+++ b/components/safe_browsing_db/v4_protocol_manager_util.h
@@ -11,11 +11,11 @@
 #include <string>
 
 #include "base/gtest_prod_util.h"
+#include "components/safe_browsing_db/safebrowsing.pb.h"
 #include "net/url_request/url_request_status.h"
 #include "url/gurl.h"
 
 namespace safe_browsing {
-
 // Config passed to the constructor of a V4 protocol manager.
 struct V4ProtocolConfig {
   // The safe browsing client name sent in each request.
@@ -28,8 +28,50 @@ struct V4ProtocolConfig {
   std::string key_param;
 };
 
+// The information required to uniquely identify each list the client is
+// interested in maintaining and downloading from the SafeBrowsing servers.
+// For example, for digests of Malware binaries on Windows:
+// platform_type = WINDOWS,
+// threat_entry_type = BINARY_DIGEST,
+// threat_type = MALWARE
+struct UpdateListIdentifier {
+  PlatformType platform_type;
+  ThreatEntryType threat_entry_type;
+  ThreatType threat_type;
+};
+
+// A class that provides static methods related to the Pver4 protocol.
 class V4ProtocolManagerUtil {
  public:
+  // Enumerate failures for histogramming purposes.  DO NOT CHANGE THE
+  // ORDERING OF THESE VALUES.
+  enum OperationResultType {
+    // 200 response code means that the server recognized the request.
+    STATUS_200 = 0,
+
+    // Subset of successful responses where the response body wasn't parsable.
+    PARSE_ERROR = 1,
+
+    // Operation request failed (network error).
+    NETWORK_ERROR = 2,
+
+    // Operation request returned HTTP result code other than 200.
+    HTTP_ERROR = 3,
+
+    // Operation attempted during error backoff, no request sent.
+    BACKOFF_ERROR = 4,
+
+    // Operation attempted before min wait duration elapsed, no request sent.
+    MIN_WAIT_DURATION_ERROR = 5,
+
+    // Identical operation already pending.
+    ALREADY_PENDING_ERROR = 6,
+
+    // Memory space for histograms is determined by the max.  ALWAYS
+    // ADD NEW VALUES BEFORE THIS ONE.
+    OPERATION_RESULT_TYPE_MAX = 7
+  };
+
   // Record HTTP response code when there's no error in fetching an HTTP
   // request, and the error code, when there is.
   // |metric_name| is the name of the UMA metric to record the response code or