Move NavThrottle enums to a common place in //chrome/browser

Bug: 1005295
Change-Id: Icc50d85dc809eec07391039c079dfaa89f47a42a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1811869Reviewed-by: Tarun Bansal <tbansal@chromium.org>
Commit-Queue: Robert Ogden <robertogden@chromium.org>
Cr-Commit-Position: refs/heads/master@{#698607}

chrome/browser/previews/previews_content_util.cc

@@ -21,6 +21,7 @@
 #include "chrome/browser/previews/previews_lite_page_decider.h"
 #include "chrome/browser/previews/previews_lite_page_navigation_throttle.h"
 #include "chrome/browser/previews/previews_lite_page_navigation_throttle_manager.h"
+#include "chrome/browser/previews/previews_lite_page_url_loader_interceptor.h"
 #include "chrome/browser/previews/previews_offline_helper.h"
 #include "chrome/browser/previews/previews_service.h"
 #include "chrome/browser/previews/previews_service_factory.h"
@@ -82,17 +83,16 @@ bool ShouldAllowRedirectPreview(content::NavigationHandle* navigation_handle) {
   PreviewsLitePageDecider* decider =
       previews_service->previews_lite_page_decider();
 
-  std::vector<PreviewsLitePageNavigationThrottle::IneligibleReason>
-      ineligible_reasons;
+  std::vector<previews::LitePageRedirectIneligibleReason> ineligible_reasons;
 
   if (!url.SchemeIs(url::kHttpsScheme)) {
     ineligible_reasons.push_back(
-        PreviewsLitePageNavigationThrottle::IneligibleReason::kNonHttpsScheme);
+        previews::LitePageRedirectIneligibleReason::kNonHttpsScheme);
   }
 
   if (decider->IsServerUnavailable()) {
-    ineligible_reasons.push_back(PreviewsLitePageNavigationThrottle::
-                                     IneligibleReason::kServerUnavailable);
+    ineligible_reasons.push_back(
+        previews::LitePageRedirectIneligibleReason::kServerUnavailable);
   }
 
   content_settings::CookieSettings* cookie_settings =
@@ -106,51 +106,46 @@ bool ShouldAllowRedirectPreview(content::NavigationHandle* navigation_handle) {
                                     &setting);
   if (!content_settings::CookieSettingsBase::IsAllowed(setting)) {
     ineligible_reasons.push_back(
-        PreviewsLitePageNavigationThrottle::IneligibleReason::kCookiesBlocked);
+        previews::LitePageRedirectIneligibleReason::kCookiesBlocked);
   }
 
   if (!decider->has_drp_headers()) {
-    ineligible_reasons.push_back(PreviewsLitePageNavigationThrottle::
-                                     IneligibleReason::kInvalidProxyHeaders);
+    ineligible_reasons.push_back(
+        previews::LitePageRedirectIneligibleReason::kInvalidProxyHeaders);
   }
 
   if (previews::params::LitePageRedirectOnlyTriggerOnSuccessfulProbe()) {
     if (!decider->IsServerProbeResultAvailable()) {
       ineligible_reasons.push_back(
-          PreviewsLitePageNavigationThrottle::IneligibleReason::
-              kServiceProbeIncomplete);
+          previews::LitePageRedirectIneligibleReason::kServiceProbeIncomplete);
     } else if (!decider->IsServerReachableByProbe()) {
-      ineligible_reasons.push_back(PreviewsLitePageNavigationThrottle::
-                                       IneligibleReason::kServiceProbeFailed);
+      ineligible_reasons.push_back(
+          previews::LitePageRedirectIneligibleReason::kServiceProbeFailed);
     }
   }
 
   // Record UMA.
-  for (PreviewsLitePageNavigationThrottle::IneligibleReason reason :
-       ineligible_reasons) {
-    PreviewsLitePageNavigationThrottle::LogIneligibleReason(reason);
+  for (previews::LitePageRedirectIneligibleReason reason : ineligible_reasons) {
+    previews::LogLitePageRedirectIneligibleReason(reason);
   }
   if (!ineligible_reasons.empty())
     return false;
 
   // Check dynamic blacklists.
-  std::vector<PreviewsLitePageNavigationThrottle::BlacklistReason>
-      blacklist_reasons;
+  std::vector<previews::LitePageRedirectBlacklistReason> blacklist_reasons;
 
   if (IsPrivateDomain(url)) {
     blacklist_reasons.push_back(
-        PreviewsLitePageNavigationThrottle::BlacklistReason::
-            kNavigationToPrivateDomain);
+        previews::LitePageRedirectBlacklistReason::kNavigationToPrivateDomain);
   }
 
   if (decider->HostBlacklistedFromBypass(url.host())) {
-    blacklist_reasons.push_back(PreviewsLitePageNavigationThrottle::
-                                    BlacklistReason::kHostBypassBlacklisted);
+    blacklist_reasons.push_back(
+        previews::LitePageRedirectBlacklistReason::kHostBypassBlacklisted);
   }
 
   // Record UMA
-  for (PreviewsLitePageNavigationThrottle::BlacklistReason reason :
-       blacklist_reasons) {
+  for (previews::LitePageRedirectBlacklistReason reason : blacklist_reasons) {
     UMA_HISTOGRAM_ENUMERATION("Previews.ServerLitePage.BlacklistReasons",
                               reason);
   }
@@ -160,8 +155,8 @@ bool ShouldAllowRedirectPreview(content::NavigationHandle* navigation_handle) {
 
   // This should always be at the end, but before the control group check.
   if (decider->NeedsToNotifyUser()) {
-    PreviewsLitePageNavigationThrottle::LogIneligibleReason(
-        PreviewsLitePageNavigationThrottle::IneligibleReason::kInfoBarNotSeen);
+    previews::LogLitePageRedirectIneligibleReason(
+        previews::LitePageRedirectIneligibleReason::kInfoBarNotSeen);
     return false;
   }
 

chrome/browser/previews/previews_lite_page_browsertest.cc

@@ -37,6 +37,7 @@
 #include "chrome/browser/metrics/subprocess_metrics_provider.h"
 #include "chrome/browser/previews/previews_lite_page_decider.h"
 #include "chrome/browser/previews/previews_lite_page_navigation_throttle.h"
+#include "chrome/browser/previews/previews_lite_page_url_loader_interceptor.h"
 #include "chrome/browser/previews/previews_service.h"
 #include "chrome/browser/previews/previews_service_factory.h"
 #include "chrome/browser/previews/previews_ui_tab_helper.h"
@@ -1027,8 +1028,7 @@ IN_PROC_BROWSER_TEST_P(
     ui_test_utils::NavigateToURL(browser(), GURL("https://0.0.0.0/"));
     histogram_tester.ExpectBucketCount(
         "Previews.ServerLitePage.BlacklistReasons",
-        PreviewsLitePageNavigationThrottle::BlacklistReason::
-            kNavigationToPrivateDomain,
+        previews::LitePageRedirectBlacklistReason::kNavigationToPrivateDomain,
         1);
     VerifyErrorPageLoaded();
   }
@@ -1041,8 +1041,7 @@ IN_PROC_BROWSER_TEST_P(
     VerifyErrorPageLoaded();
     histogram_tester.ExpectBucketCount(
         "Previews.ServerLitePage.BlacklistReasons",
-        PreviewsLitePageNavigationThrottle::BlacklistReason::
-            kNavigationToPrivateDomain,
+        previews::LitePageRedirectBlacklistReason::kNavigationToPrivateDomain,
         1);
   }
 
@@ -1099,8 +1098,7 @@ IN_PROC_BROWSER_TEST_P(
     VerifyPreviewNotLoaded();
     histogram_tester.ExpectBucketCount(
         "Previews.ServerLitePage.IneligibleReasons",
-        PreviewsLitePageNavigationThrottle::IneligibleReason::kCookiesBlocked,
-        1);
+        previews::LitePageRedirectIneligibleReason::kCookiesBlocked, 1);
 
     // Reset state for other tests.
     CookieSettingsFactory::GetForProfile(browser()->profile())
@@ -1191,8 +1189,8 @@ IN_PROC_BROWSER_TEST_P(
 
   histogram_tester.ExpectBucketCount(
       "Previews.ServerLitePage.IneligibleReasons",
-      static_cast<int>(PreviewsLitePageNavigationThrottle::IneligibleReason::
-                           kInvalidProxyHeaders),
+      static_cast<int>(
+          previews::LitePageRedirectIneligibleReason::kInvalidProxyHeaders),
       1);
 }
 
@@ -1273,7 +1271,7 @@ IN_PROC_BROWSER_TEST_P(PreviewsLitePageServerBrowserTest,
     ClearDeciderState();
     histogram_tester.ExpectBucketCount(
         "Previews.ServerLitePage.ServerResponse",
-        PreviewsLitePageNavigationThrottle::ServerResponse::kRedirect, 1);
+        previews::LitePageRedirectServerResponse::kRedirect, 1);
   }
 
   {
@@ -1286,10 +1284,10 @@ IN_PROC_BROWSER_TEST_P(PreviewsLitePageServerBrowserTest,
 
     histogram_tester.ExpectBucketCount(
         "Previews.ServerLitePage.ServerResponse",
-        PreviewsLitePageNavigationThrottle::ServerResponse::kRedirect, 1);
+        previews::LitePageRedirectServerResponse::kRedirect, 1);
     histogram_tester.ExpectBucketCount(
         "Previews.ServerLitePage.ServerResponse",
-        PreviewsLitePageNavigationThrottle::ServerResponse::kOk, 1);
+        previews::LitePageRedirectServerResponse::kOk, 1);
   }
 }
 
@@ -1304,8 +1302,7 @@ IN_PROC_BROWSER_TEST_P(PreviewsLitePageServerBrowserTest,
     ClearDeciderState();
     histogram_tester.ExpectBucketCount(
         "Previews.ServerLitePage.ServerResponse",
-        PreviewsLitePageNavigationThrottle::ServerResponse::kPreviewUnavailable,
-        1);
+        previews::LitePageRedirectServerResponse::kPreviewUnavailable, 1);
 
     histogram_tester.ExpectBucketCount(
         "Previews.ServerLitePage.HostBlacklistedOnBypass", false, 1);
@@ -1321,8 +1318,7 @@ IN_PROC_BROWSER_TEST_P(PreviewsLitePageServerBrowserTest,
 
     histogram_tester.ExpectBucketCount(
         "Previews.ServerLitePage.ServerResponse",
-        PreviewsLitePageNavigationThrottle::ServerResponse::kPreviewUnavailable,
-        1);
+        previews::LitePageRedirectServerResponse::kPreviewUnavailable, 1);
     histogram_tester.ExpectBucketCount(
         "Previews.ServerLitePage.HostBlacklistedOnBypass", true, 1);
 
@@ -1330,9 +1326,7 @@ IN_PROC_BROWSER_TEST_P(PreviewsLitePageServerBrowserTest,
     VerifyPreviewNotLoaded();
     histogram_tester.ExpectBucketCount(
         "Previews.ServerLitePage.BlacklistReasons",
-        PreviewsLitePageNavigationThrottle::BlacklistReason::
-            kHostBypassBlacklisted,
-        1);
+        previews::LitePageRedirectBlacklistReason::kHostBypassBlacklisted, 1);
     ClearDeciderState();
 
     ui_test_utils::NavigateToURL(browser(), HttpsLitePageURL(kSuccess));
@@ -1347,7 +1341,7 @@ IN_PROC_BROWSER_TEST_P(PreviewsLitePageServerBrowserTest,
     ClearDeciderState();
     histogram_tester.ExpectBucketCount(
         "Previews.ServerLitePage.ServerResponse",
-        PreviewsLitePageNavigationThrottle::ServerResponse::kAuthFailure, 1);
+        previews::LitePageRedirectServerResponse::kAuthFailure, 1);
   }
 
   {
@@ -1358,8 +1352,7 @@ IN_PROC_BROWSER_TEST_P(PreviewsLitePageServerBrowserTest,
     ClearDeciderState();
     histogram_tester.ExpectBucketCount(
         "Previews.ServerLitePage.ServerResponse",
-        PreviewsLitePageNavigationThrottle::ServerResponse::kServiceUnavailable,
-        1);
+        previews::LitePageRedirectServerResponse::kServiceUnavailable, 1);
   }
 }
 
@@ -1607,7 +1600,7 @@ IN_PROC_BROWSER_TEST_P(PreviewsLitePageServerTimeoutBrowserTest,
     ClearDeciderState();
     histogram_tester.ExpectBucketCount(
         "Previews.ServerLitePage.ServerResponse",
-        PreviewsLitePageNavigationThrottle::ServerResponse::kTimeout, 1);
+        previews::LitePageRedirectServerResponse::kTimeout, 1);
   }
 
   {
@@ -1658,9 +1651,7 @@ IN_PROC_BROWSER_TEST_P(
     VerifyPreviewNotLoaded();
     histogram_tester.ExpectBucketCount(
         "Previews.ServerLitePage.IneligibleReasons",
-        PreviewsLitePageNavigationThrottle::IneligibleReason::
-            kServiceProbeFailed,
-        1);
+        previews::LitePageRedirectIneligibleReason::kServiceProbeFailed, 1);
   }
 }
 
@@ -1786,7 +1777,7 @@ IN_PROC_BROWSER_TEST_P(
                 ->GetMessageText());
   histogram_tester.ExpectBucketCount(
       "Previews.ServerLitePage.IneligibleReasons",
-      PreviewsLitePageNavigationThrottle::IneligibleReason::kInfoBarNotSeen, 1);
+      previews::LitePageRedirectIneligibleReason::kInfoBarNotSeen, 1);
 }
 
 class PreviewsLitePageDSDisabledBrowserTest

chrome/browser/previews/previews_lite_page_navigation_throttle.cc

@@ -65,14 +65,6 @@ bool HandlePreviewsLitePageURLRewriteReverse(
   return false;
 }
 
-// static
-void PreviewsLitePageNavigationThrottle::LogIneligibleReason(
-    IneligibleReason reason) {
-  UMA_HISTOGRAM_ENUMERATION("Previews.ServerLitePage.IneligibleReasons",
-
-                            reason);
-}
-
 // static
 GURL PreviewsLitePageNavigationThrottle::GetPreviewsURLForURL(
     const GURL& original_url) {

chrome/browser/previews/previews_lite_page_navigation_throttle.h

@@ -33,85 +33,9 @@ bool HandlePreviewsLitePageURLRewriteReverse(
 
 class PreviewsLitePageNavigationThrottle {
  public:
-  // Reasons that a navigation is blacklisted from this preview. This enum must
-  // remain synchronized with the enum |PreviewsServerLitePageBlacklistReason|
-  // in tools/metrics/histograms/enums.xml.
-  enum class BlacklistReason {
-    kPathSuffixBlacklisted_DEPRECATED = 0,
-    kNavigationToPreviewsDomain = 1,
-    kNavigationToPrivateDomain = 2,
-    kHostBypassBlacklisted = 3,
-    kMaxValue = kHostBypassBlacklisted,
-  };
-
-  // Reasons that a navigation is not eligible for this preview. This enum must
-  // remain synchronized with the enum |PreviewsServerLitePageIneligibleReason|
-  // in tools/metrics/histograms/enums.xml.
-  enum class IneligibleReason {
-    kNonHttpsScheme = 0,
-    kHttpPost_DEPRECATED = 1,
-    kSubframeNavigation = 2,
-    kServerUnavailable = 3,
-    kInfoBarNotSeen = 4,
-    kNetworkNotSlow_DEPRECATED = 5,
-    kLoadOriginalReload = 6,
-    kCookiesBlocked = 7,
-    kECTUnknown_DEPRECATED = 8,
-    kExceededMaxNavigationRestarts = 9,
-    kPreviewsState_DEPRECATED = 10,
-    kInvalidProxyHeaders = 11,
-    kServiceProbeIncomplete = 12,
-    kServiceProbeFailed = 13,
-    kMaxValue = kServiceProbeFailed,
-  };
-
-  // The response type from the previews server. This enum must
-  // remain synchronized with the enum |PreviewsServerLitePageServerResponse| in
-  // tools/metrics/histograms/enums.xml.
-  enum class ServerResponse {
-    // A preview was served (HTTP 200).
-    kOk = 0,
-
-    // The client was redirected to another page (HTTP 307).
-    kRedirect = 1,
-
-    // The requested preview was not available (HTTP 307).
-    kPreviewUnavailable = 2,
-
-    // The previews server is not available (HTTP 503).
-    kServiceUnavailable = 3,
-
-    // The previews server responded with some other HTTP code.
-    kOther = 4,
-
-    // There was some network error and we did not get a response from the
-    // previews server.
-    kFailed = 5,
-
-    // The previews server did not respond after a timeout.
-    kTimeout = 6,
-
-    // The previews server rejected our authentication (HTTP 403).
-    kAuthFailure = 7,
-
-    // No response headers were available from the preview server.
-    kNoResponseHeaders = 8,
-
-    // The connection was closed without getting a response.
-    kOnCompleteBeforeOnResponse = 9,
-
-    // There was an error connecting to the previews server.
-    kConnectionError = 10,
-
-    kMaxValue = kConnectionError,
-  };
-
   // Returns the URL for a preview given by the url.
   static GURL GetPreviewsURLForURL(const GURL& original_url);
 
-  // Records an entry in the ineligibility histogram.
-  static void LogIneligibleReason(IneligibleReason reason);
-
   // Gets the ServerLitePageInfo struct from an existing attempted lite page
   // navigation, if there is one. If not, returns a new ServerLitePageInfo
   // initialized with metadata from navigation_handle() and |this| that is owned

chrome/browser/previews/previews_lite_page_serving_url_loader.cc

@@ -21,8 +21,8 @@
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/time.h"
 #include "chrome/browser/previews/previews_lite_page_decider.h"
-#include "chrome/browser/previews/previews_lite_page_navigation_throttle.h"
 #include "chrome/browser/previews/previews_lite_page_navigation_throttle_manager.h"
+#include "chrome/browser/previews/previews_lite_page_url_loader_interceptor.h"
 #include "chrome/browser/previews/previews_service.h"
 #include "chrome/browser/previews/previews_service_factory.h"
 #include "chrome/browser/profiles/profile.h"
@@ -195,9 +195,8 @@ void PreviewsLitePageServingURLLoader::Timeout() {
   if (result_callback_.is_null())
     return;
 
-  UMA_HISTOGRAM_ENUMERATION(
-      "Previews.ServerLitePage.ServerResponse",
-      PreviewsLitePageNavigationThrottle::ServerResponse::kTimeout);
+  UMA_HISTOGRAM_ENUMERATION("Previews.ServerLitePage.ServerResponse",
+                            previews::LitePageRedirectServerResponse::kTimeout);
 
   Fallback();
 }
@@ -259,16 +258,16 @@ void PreviewsLitePageServingURLLoader::OnReceiveResponse(
   if (!response_headers) {
     UMA_HISTOGRAM_ENUMERATION(
         "Previews.ServerLitePage.ServerResponse",
-        PreviewsLitePageNavigationThrottle::ServerResponse::kNoResponseHeaders);
+        previews::LitePageRedirectServerResponse::kNoResponseHeaders);
     Fallback();
     return;
   }
 
   if (response_headers->response_code() != net::HTTP_OK) {
     if (response_headers->response_code() == net::HTTP_SERVICE_UNAVAILABLE) {
-      UMA_HISTOGRAM_ENUMERATION("Previews.ServerLitePage.ServerResponse",
-                                PreviewsLitePageNavigationThrottle::
-                                    ServerResponse::kServiceUnavailable);
+      UMA_HISTOGRAM_ENUMERATION(
+          "Previews.ServerLitePage.ServerResponse",
+          previews::LitePageRedirectServerResponse::kServiceUnavailable);
       std::string retry_after_header;
       base::TimeDelta retry_after = base::TimeDelta::FromSeconds(base::RandInt(
           60, previews::params::PreviewServerLoadshedMaxSeconds()));
@@ -281,20 +280,19 @@ void PreviewsLitePageServingURLLoader::OnReceiveResponse(
     } else if (response_headers->response_code() == net::HTTP_FORBIDDEN) {
       UMA_HISTOGRAM_ENUMERATION(
           "Previews.ServerLitePage.ServerResponse",
-          PreviewsLitePageNavigationThrottle::ServerResponse::kAuthFailure);
+          previews::LitePageRedirectServerResponse::kAuthFailure);
     } else {
       UMA_HISTOGRAM_ENUMERATION(
           "Previews.ServerLitePage.ServerResponse",
-          PreviewsLitePageNavigationThrottle::ServerResponse::kOther);
+          previews::LitePageRedirectServerResponse::kOther);
     }
 
     Fallback();
     return;
   }
 
-  UMA_HISTOGRAM_ENUMERATION(
-      "Previews.ServerLitePage.ServerResponse",
-      PreviewsLitePageNavigationThrottle::ServerResponse::kOk);
+  UMA_HISTOGRAM_ENUMERATION("Previews.ServerLitePage.ServerResponse",
+                            previews::LitePageRedirectServerResponse::kOk);
 
   // Store head and pause new messages until the forwarding client is set up.
   // Make a deep copy of ResourceResponseHead before passing it cross-thread.
@@ -333,9 +331,9 @@ void PreviewsLitePageServingURLLoader::OnReceiveRedirect(
   if (previews::ExtractOriginalURLFromLitePageRedirectURL(previews_url_,
                                                           &original_url) &&
       GURL(original_url) == redirect_info.new_url) {
-    UMA_HISTOGRAM_ENUMERATION("Previews.ServerLitePage.ServerResponse",
-                              PreviewsLitePageNavigationThrottle::
-                                  ServerResponse::kPreviewUnavailable);
+    UMA_HISTOGRAM_ENUMERATION(
+        "Previews.ServerLitePage.ServerResponse",
+        previews::LitePageRedirectServerResponse::kPreviewUnavailable);
     const net::HttpResponseHeaders* response_headers = head->headers.get();
 
     std::string chrome_proxy_header;
@@ -359,7 +357,7 @@ void PreviewsLitePageServingURLLoader::OnReceiveRedirect(
 
   UMA_HISTOGRAM_ENUMERATION(
       "Previews.ServerLitePage.ServerResponse",
-      PreviewsLitePageNavigationThrottle::ServerResponse::kRedirect);
+      previews::LitePageRedirectServerResponse::kRedirect);
 
   std::move(result_callback_)
       .Run(ServingLoaderResult::kRedirect, redirect_info, resource_response_);
@@ -405,9 +403,9 @@ void PreviewsLitePageServingURLLoader::OnComplete(
       "Previews.ServerLitePage.ServerNetError.BeforeCommit",
       -status.error_code);
 
-  UMA_HISTOGRAM_ENUMERATION("Previews.ServerLitePage.ServerResponse",
-                            PreviewsLitePageNavigationThrottle::ServerResponse::
-                                kOnCompleteBeforeOnResponse);
+  UMA_HISTOGRAM_ENUMERATION(
+      "Previews.ServerLitePage.ServerResponse",
+      previews::LitePageRedirectServerResponse::kOnCompleteBeforeOnResponse);
 
   // If OnComplete is called before, OnReceiveResponse, this is indicative of a
   // failure of some sort.
@@ -449,7 +447,7 @@ void PreviewsLitePageServingURLLoader::OnConnectionError() {
   if (!result_callback_.is_null()) {
     UMA_HISTOGRAM_ENUMERATION(
         "Previews.ServerLitePage.ServerResponse",
-        PreviewsLitePageNavigationThrottle::ServerResponse::kConnectionError);
+        previews::LitePageRedirectServerResponse::kConnectionError);
     Fallback();
     return;
   }

chrome/browser/previews/previews_lite_page_url_loader_interceptor.cc

@@ -77,6 +77,12 @@ net::HttpRequestHeaders GetChromeProxyHeaders(
 
 }  // namespace
 
+void LogLitePageRedirectIneligibleReason(
+    LitePageRedirectIneligibleReason reason) {
+  UMA_HISTOGRAM_ENUMERATION("Previews.ServerLitePage.IneligibleReasons",
+                            reason);
+}
+
 PreviewsLitePageURLLoaderInterceptor::PreviewsLitePageURLLoaderInterceptor(
     const scoped_refptr<network::SharedURLLoaderFactory>&
         network_loader_factory,

chrome/browser/previews/previews_lite_page_url_loader_interceptor.h

@@ -21,6 +21,85 @@
 
 namespace previews {
 
+// Reasons that a navigation is blacklisted from a lite page redirect preview.
+// This enum must remain synchronized with the enum
+// |PreviewsServerLitePageBlacklistReason| in
+// tools/metrics/histograms/enums.xml.
+enum class LitePageRedirectBlacklistReason {
+  // DEPRECATED: kPathSuffixBlacklisted = 0,
+  kNavigationToPreviewsDomain = 1,
+  kNavigationToPrivateDomain = 2,
+  kHostBypassBlacklisted = 3,
+  kMaxValue = kHostBypassBlacklisted,
+};
+
+// Reasons that a navigation is not eligible for a lite page redirect preview.
+// This enum must remain synchronized with the enum
+// |PreviewsServerLitePageIneligibleReason| in
+// tools/metrics/histograms/enums.xml.
+enum class LitePageRedirectIneligibleReason {
+  kNonHttpsScheme = 0,
+  // DEPRECATED: kHttpPost = 1,
+  kSubframeNavigation = 2,
+  kServerUnavailable = 3,
+  kInfoBarNotSeen = 4,
+  // DEPRECATED: kNetworkNotSlow = 5,
+  kLoadOriginalReload = 6,
+  kCookiesBlocked = 7,
+  // DEPRECATED: kECTUnknown = 8,
+  kExceededMaxNavigationRestarts = 9,
+  // DEPRECATED: kPreviewsState = 10,
+  kInvalidProxyHeaders = 11,
+  kServiceProbeIncomplete = 12,
+  kServiceProbeFailed = 13,
+  kMaxValue = kServiceProbeFailed,
+};
+
+// The response type from the previews server. This enum must
+// remain synchronized with the enum |PreviewsServerLitePageServerResponse| in
+// tools/metrics/histograms/enums.xml.
+enum class LitePageRedirectServerResponse {
+  // A preview was served (HTTP 200).
+  kOk = 0,
+
+  // The client was redirected to another page (HTTP 307).
+  kRedirect = 1,
+
+  // The requested preview was not available (HTTP 307).
+  kPreviewUnavailable = 2,
+
+  // The previews server is not available (HTTP 503).
+  kServiceUnavailable = 3,
+
+  // The previews server responded with some other HTTP code.
+  kOther = 4,
+
+  // There was some network error and we did not get a response from the
+  // previews server.
+  kFailed = 5,
+
+  // The previews server did not respond after a timeout.
+  kTimeout = 6,
+
+  // The previews server rejected our authentication (HTTP 403).
+  kAuthFailure = 7,
+
+  // No response headers were available from the preview server.
+  kNoResponseHeaders = 8,
+
+  // The connection was closed without getting a response.
+  kOnCompleteBeforeOnResponse = 9,
+
+  // There was an error connecting to the previews server.
+  kConnectionError = 10,
+
+  kMaxValue = kConnectionError,
+};
+
+// Records an entry in the lite page redirect ineligibility histogram.
+void LogLitePageRedirectIneligibleReason(
+    LitePageRedirectIneligibleReason reason);
+
 // A class that attempts to intercept requests and fetch the Lite Page version
 // of the request. Its lifetime matches that of the content/ navigation loader
 // code. Currently, not fully implemented.