Move common PVer4 code into a V4ProtocolManagerUtil class.

components/safe_browsing_db/v4_protocol_manager_util.cc

Index: components/safe_browsing_db/v4_protocol_manager_util.cc
diff --git a/components/safe_browsing_db/v4_protocol_manager_util.cc b/components/safe_browsing_db/v4_protocol_manager_util.cc
new file mode 100644
index 0000000000000000000000000000000000000000..5f91bfbaab0672c2a94b56fc9208ba54f76176bf
--- /dev/null
+++ b/components/safe_browsing_db/v4_protocol_manager_util.cc
@@ -0,0 +1,86 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "components/safe_browsing_db/v4_protocol_manager_util.h"
+
+#include "base/base64.h"
+#include "base/metrics/sparse_histogram.h"
+#include "base/rand_util.h"
+#include "base/strings/stringprintf.h"
+#include "net/base/escape.h"
+
+using base::Time;
+using base::TimeDelta;
+
+namespace safe_browsing {
+
+// The Safe Browsing V4 server URL prefix.
+const char kSbV4UrlPrefix[] = "https://safebrowsing.googleapis.com/v4";
+
+// static
+// Backoff interval is MIN(((2^(n-1))*15 minutes) * (RAND + 1), 24 hours) where
+// n is the number of consecutive errors.
+base::TimeDelta V4ProtocolManagerUtil::GetNextBackOffInterval(
+    size_t* error_count,
+    size_t* multiplier) {
+  DCHECK(multiplier && error_count);
+  (*error_count)++;
+  if (*error_count > 1 && *error_count < 9) {
+    // With error count 9 and above we will hit the 24 hour max interval.
+    // Cap the multiplier here to prevent integer overflow errors.
+    *multiplier *= 2;
+  }
+  base::TimeDelta next =
+      base::TimeDelta::FromMinutes(*multiplier * (1 + base::RandDouble()) * 15);
+
+  base::TimeDelta day = base::TimeDelta::FromHours(24);
+
+  if (next < day)
+    return next;
+  else
+    return day;
+}
+
+// static
+void V4ProtocolManagerUtil::RecordHttpResponseOrErrorCode(
+    const char* metric_name,
+    const net::URLRequestStatus& status,
+    int response_code) {
+  UMA_HISTOGRAM_SPARSE_SLOWLY(
+      metric_name, status.is_success() ? response_code : status.error());
+}
+
+// static
+// The API hash call uses the pver4 Safe Browsing server.
+GURL V4ProtocolManagerUtil::GetRequestUrl(
+    const std::string& request_base64, const std::string& method_name,
+    const V4ProtocolConfig& config) {
+  std::string url =
+      ComposeUrl(kSbV4UrlPrefix, method_name, request_base64,
+                 config.client_name, config.version, config.key_param);
+  return GURL(url);
+}
+
+// static
+std::string V4ProtocolManagerUtil::ComposeUrl(
+    const std::string& prefix,
+    const std::string& method,
+    const std::string& request_base64,
+    const std::string& client_id,
+    const std::string& version,
+    const std::string& key_param) {
+  DCHECK(!prefix.empty() && !method.empty() && !client_id.empty() &&
+         !version.empty());
+  std::string url =
+      base::StringPrintf("%s/%s/%s?alt=proto&client_id=%s&client_version=%s",
+                         prefix.c_str(), method.c_str(), request_base64.c_str(),
+                         client_id.c_str(), version.c_str());
+  if (!key_param.empty()) {
+    base::StringAppendF(&url, "&key=%s",
+                        net::EscapeQueryParamValue(key_param, true).c_str());
+  }
+  return url;
+}
+
+}  // namespace safe_browsing