Fix UMA reporting of data reduction proxy bypass reasons

5xx responses from the proxy that should induce proxy bypass were previously reported as bypassing due to a missing via header value, because such responses often also are missing that header value. This change fixes that reporting.

BUG=356445

Review URL: https://codereview.chromium.org/212873004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@260598 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 123 insertions, 25 deletions

diff --git a/net/http/http_network_transaction.cc b/net/http/http_network_transaction.cc
index ba27cb7..3d58afd 100644
--- a/net/http/http_network_transaction.cc
+++ b/net/http/http_network_transaction.cc
@@ -995,7 +995,6 @@ int HttpNetworkTransaction::DoReadHeadersComplete(int result) {
   if (response_.was_fetched_via_proxy) {
     ProxyService::DataReductionProxyBypassEventType proxy_bypass_event =
         ProxyService::BYPASS_EVENT_TYPE_MAX;
-    net::HttpResponseHeaders::ChromeProxyInfo chrome_proxy_info;
     bool chrome_proxy_used =
         proxy_info_.proxy_server().isDataReductionProxy();
     bool chrome_fallback_proxy_used = false;
@@ -1007,29 +1006,9 @@ int HttpNetworkTransaction::DoReadHeadersComplete(int result) {
 #endif
 
     if (chrome_proxy_used || chrome_fallback_proxy_used) {
-      // A Via header might not be present in a 304. Since the goal of a 304
-      // response is to minimize information transfer, a sender in general
-      // should not generate representation metadata other than Cache-Control,
-      // Content-Location, Date, ETag, Expires, and Vary.
-      if (!response_.headers->IsChromeProxyResponse() &&
-          (response_.headers->response_code() != HTTP_NOT_MODIFIED)) {
-        proxy_bypass_event = ProxyService::MISSING_VIA_HEADER;
-      } else if (response_.headers->GetChromeProxyInfo(&chrome_proxy_info)) {
-        if (chrome_proxy_info.bypass_duration < TimeDelta::FromMinutes(30))
-          proxy_bypass_event = ProxyService::SHORT_BYPASS;
-        else
-          proxy_bypass_event = ProxyService::LONG_BYPASS;
-      } else {
-        // Additionally, fallback if a 500, 502 or 503 is returned via the data
-        // reduction proxy. This is conservative, as the 500, 502 or 503 might
-        // have been generated by the origin, and not the proxy.
-        if (response_.headers->response_code() == HTTP_INTERNAL_SERVER_ERROR ||
-            response_.headers->response_code() == HTTP_BAD_GATEWAY ||
-            response_.headers->response_code() == HTTP_SERVICE_UNAVAILABLE) {
-          proxy_bypass_event = ProxyService::INTERNAL_SERVER_ERROR_BYPASS;
-        }
-      }
-
+      net::HttpResponseHeaders::ChromeProxyInfo chrome_proxy_info;
+      proxy_bypass_event = response_.headers->GetChromeProxyBypassEventType(
+          &chrome_proxy_info);
       if (proxy_bypass_event < ProxyService::BYPASS_EVENT_TYPE_MAX) {
         ProxyService* proxy_service = session_->proxy_service();
 
diff --git a/net/http/http_response_headers.cc b/net/http/http_response_headers.cc
index f6e3658..c067e8f 100644
--- a/net/http/http_response_headers.cc
+++ b/net/http/http_response_headers.cc
@@ -26,6 +26,11 @@
 #include "net/http/http_log_util.h"
 #include "net/http/http_util.h"
 
+#if defined(SPDY_PROXY_AUTH_ORIGIN)
+#include "net/http/http_status_code.h"
+#include "net/proxy/proxy_service.h"
+#endif
+
 using base::StringPiece;
 using base::Time;
 using base::TimeDelta;
@@ -1417,7 +1422,6 @@ bool HttpResponseHeaders::GetChromeProxyInfo(
   DCHECK(proxy_info);
   proxy_info->bypass_all = false;
   proxy_info->bypass_duration = base::TimeDelta();
-
   // Support header of the form Chrome-Proxy: bypass|block=<duration>, where
   // <duration> is the number of seconds to wait before retrying
   // the proxy. If the duration is 0, then the default proxy retry delay
@@ -1464,6 +1468,34 @@ bool HttpResponseHeaders::IsChromeProxyResponse() const {
 
   return false;
 }
+
+ProxyService::DataReductionProxyBypassEventType
+HttpResponseHeaders::GetChromeProxyBypassEventType(
+    ChromeProxyInfo* chrome_proxy_info) const {
+  DCHECK(chrome_proxy_info);
+  if (GetChromeProxyInfo(chrome_proxy_info)) {
+    // A chrome-proxy response header is only present in a 502. For proper
+    // reporting, this check must come before the 5xx checks below.
+    if (chrome_proxy_info->bypass_duration < TimeDelta::FromMinutes(30))
+      return ProxyService::SHORT_BYPASS;
+    return ProxyService::LONG_BYPASS;
+  }
+  if (response_code() == HTTP_INTERNAL_SERVER_ERROR ||
+      response_code() == HTTP_BAD_GATEWAY ||
+      response_code() == HTTP_SERVICE_UNAVAILABLE) {
+    // Fall back if a 500, 502 or 503 is returned.
+    return ProxyService::INTERNAL_SERVER_ERROR_BYPASS;
+  }
+  if (!IsChromeProxyResponse() && (response_code() != HTTP_NOT_MODIFIED)) {
+    // A Via header might not be present in a 304. Since the goal of a 304
+    // response is to minimize information transfer, a sender in general
+    // should not generate representation metadata other than Cache-Control,
+    // Content-Location, Date, ETag, Expires, and Vary.
+    return ProxyService::MISSING_VIA_HEADER;
+  }
+  // There is no bypass event.
+  return ProxyService::BYPASS_EVENT_TYPE_MAX;
+}
 #endif  // defined(SPDY_PROXY_AUTH_ORIGIN)
 
 }  // namespace net
diff --git a/net/http/http_response_headers.h b/net/http/http_response_headers.h
index 2eb0c67..62207ed 100644
--- a/net/http/http_response_headers.h
+++ b/net/http/http_response_headers.h
@@ -16,6 +16,10 @@
 #include "net/base/net_log.h"
 #include "net/http/http_version.h"
 
+#if defined(SPDY_PROXY_AUTH_ORIGIN)
+#include "net/proxy/proxy_service.h"
+#endif
+
 class Pickle;
 class PickleIterator;
 
@@ -286,6 +290,12 @@ class NET_EXPORT HttpResponseHeaders
 
   // Returns true if response headers contain the Chrome proxy Via header value.
   bool IsChromeProxyResponse() const;
+
+  // Returns the reason why the Chrome proxy should be bypassed or not, and
+  // populates |proxy_info| with information on how long to bypass if
+  // applicable.
+  ProxyService::DataReductionProxyBypassEventType
+  GetChromeProxyBypassEventType(ChromeProxyInfo* proxy_info) const;
 #endif
 
   // Creates a Value for use with the NetLog containing the response headers.
diff --git a/net/http/http_response_headers_unittest.cc b/net/http/http_response_headers_unittest.cc
index 0b17b8f..f73e176 100644
--- a/net/http/http_response_headers_unittest.cc
+++ b/net/http/http_response_headers_unittest.cc
@@ -13,6 +13,10 @@
 #include "net/http/http_response_headers.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
+#if defined(SPDY_PROXY_AUTH_ORIGIN)
+#include "net/proxy/proxy_service.h"
+#endif
+
 namespace {
 
 struct TestData {
@@ -2172,4 +2176,77 @@ TEST(HttpResponseHeadersTest, IsChromeProxyResponse) {
     EXPECT_EQ(tests[i].expected_result, parsed->IsChromeProxyResponse());
   }
 }
+
+TEST(HttpResponseHeadersTest, GetChromeProxyBypassEventType) {
+  const struct {
+     const char* headers;
+     net::ProxyService::DataReductionProxyBypassEventType expected_result;
+  } tests[] = {
+    { "HTTP/1.1 200 OK\n"
+      "Chrome-Proxy: bypass=0\n"
+      "Via: 1.1 Chrome-Compression-Proxy\n",
+      net::ProxyService::SHORT_BYPASS,
+    },
+    { "HTTP/1.1 200 OK\n"
+      "Chrome-Proxy: bypass=1799\n"
+      "Via: 1.1 Chrome-Compression-Proxy\n",
+      net::ProxyService::SHORT_BYPASS,
+    },
+    { "HTTP/1.1 200 OK\n"
+      "Chrome-Proxy: bypass=1800\n"
+      "Via: 1.1 Chrome-Compression-Proxy\n",
+      net::ProxyService::LONG_BYPASS,
+    },
+    { "HTTP/1.1 500 Internal Server Error\n"
+      "Via: 1.1 Chrome-Compression-Proxy\n",
+      net::ProxyService::INTERNAL_SERVER_ERROR_BYPASS,
+    },
+    { "HTTP/1.1 501 Not Implemented\n"
+      "Via: 1.1 Chrome-Compression-Proxy\n",
+      net::ProxyService::BYPASS_EVENT_TYPE_MAX,
+    },
+    { "HTTP/1.1 502 Bad Gateway\n"
+      "Via: 1.1 Chrome-Compression-Proxy\n",
+      net::ProxyService::INTERNAL_SERVER_ERROR_BYPASS,
+    },
+    { "HTTP/1.1 503 Service Unavailable\n"
+      "Via: 1.1 Chrome-Compression-Proxy\n",
+      net::ProxyService::INTERNAL_SERVER_ERROR_BYPASS,
+    },
+    { "HTTP/1.1 504 Gateway Timeout\n"
+      "Via: 1.1 Chrome-Compression-Proxy\n",
+      net::ProxyService::BYPASS_EVENT_TYPE_MAX,
+    },
+    { "HTTP/1.1 505 HTTP Version Not Supported\n"
+      "Via: 1.1 Chrome-Compression-Proxy\n",
+      net::ProxyService::BYPASS_EVENT_TYPE_MAX,
+    },
+    { "HTTP/1.1 304 Not Modified\n",
+        net::ProxyService::BYPASS_EVENT_TYPE_MAX,
+    },
+    { "HTTP/1.1 200 OK\n",
+        net::ProxyService::MISSING_VIA_HEADER,
+    },
+    { "HTTP/1.1 200 OK\n"
+      "Chrome-Proxy: bypass=1799\n",
+      net::ProxyService::SHORT_BYPASS,
+    },
+    { "HTTP/1.1 502 Bad Gateway\n",
+      net::ProxyService::INTERNAL_SERVER_ERROR_BYPASS,
+    },
+    { "HTTP/1.1 502 Bad Gateway\n"
+      "Chrome-Proxy: bypass=1799\n",
+      net::ProxyService::SHORT_BYPASS,
+    },
+  };
+  for (size_t i = 0; i < ARRAYSIZE_UNSAFE(tests); ++i) {
+    std::string headers(tests[i].headers);
+    HeadersToRaw(&headers);
+    scoped_refptr<net::HttpResponseHeaders> parsed(
+        new net::HttpResponseHeaders(headers));
+    net::HttpResponseHeaders::ChromeProxyInfo chrome_proxy_info;
+    EXPECT_EQ(tests[i].expected_result,
+              parsed->GetChromeProxyBypassEventType(&chrome_proxy_info));
+  }
+}
 #endif  // defined(SPDY_PROXY_AUTH_ORIGIN)