Revert "Add Sec-CH-UA-Reduced client hint header when Origin Trial to…

…ken present"

This reverts commit d9c057e.

Reason for revert: Browser tests is failing on linux-chromeos-chrome.
See [1].

[1] https://ci.chromium.org/ui/p/chrome/builders/ci/linux-chromeos-chrome/16242/overview

Original change's description:
> Add Sec-CH-UA-Reduced client hint header when Origin Trial token present
>
> In this CL, we add logic to parse and accept the Sec-CH-UA-Reduced
> client hint in the Accept-CH header and and only send the
> Sec-CH-UA-Reduced client hint only in the presence of a valid
> UserAgentReduction Origin Trial token.
>
> If the Origin Trial token is present and valid, and the origin
> contains Sec-CH-UA-Reduced in the Accept-CH cache, then on all
> subsequent requests to the origin, the Sec-CH-UA-Reduced request
> header will be set with a value of "?1" (sh-boolean).  If the
> Accept-CH cache does not contain Sec-CH-UA-Reduced, or the Origin
> Trial token is not valid, then Sec-CH-UA-Reduced will not be sent
> in the request headers.
>
> NB: A subsequent CL will change the User-Agent request header to
> the reduced UA string if the Sec-CH-UA-Reduced header is sent.
>
> Chrome Platform Status: https://chromestatus.com/feature/5704553745874944
> Design Doc: https://docs.google.com/document/d/1feIxK9S7oNgT2oGGebbxE9X0O-4wTKcsP_gRaY99tq4
>
> Bug: 1222742
> Change-Id: If855d4bb393540d49de3be80aa9bc7c80f861c50
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3042810
> Commit-Queue: Ali Beyad <abeyad@chromium.org>
> Reviewed-by: Aaron Tagliaboschi <aarontag@chromium.org>
> Reviewed-by: Robert Kroeger <rjkroege@chromium.org>
> Reviewed-by: Mike West <mkwst@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#906810}

Bug: 1222742
Change-Id: I0d8aab1d56d78f8323d4a3e3ed88b6eef370e1b9
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3061119
Auto-Submit: Daniel Hosseinian <dhoss@chromium.org>
Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Owners-Override: Daniel Hosseinian <dhoss@chromium.org>
Cr-Commit-Position: refs/heads/master@{#906884}

chrome/browser/client_hints/client_hints_browsertest.cc

@@ -11,10 +11,8 @@
 #include "base/containers/contains.h"
 #include "base/metrics/field_trial_param_associator.h"
 #include "base/run_loop.h"
-#include "base/strings/strcat.h"
 #include "base/strings/string_util.h"
 #include "base/synchronization/lock.h"
-#include "base/test/bind.h"
 #include "base/test/metrics/histogram_tester.h"
 #include "build/build_config.h"
 #include "chrome/browser/content_settings/cookie_settings_factory.h"
@@ -30,7 +28,6 @@
 #include "components/content_settings/core/browser/cookie_settings.h"
 #include "components/content_settings/core/browser/host_content_settings_map.h"
 #include "components/content_settings/core/common/pref_names.h"
-#include "components/embedder_support/switches.h"
 #include "components/embedder_support/user_agent_utils.h"
 #include "components/metrics/content/subprocess_metrics_provider.h"
 #include "components/page_load_metrics/browser/page_load_metrics_test_waiter.h"
@@ -42,8 +39,6 @@
 #include "content/public/common/content_switches.h"
 #include "content/public/test/browser_test.h"
 #include "content/public/test/browser_test_utils.h"
-#include "content/public/test/content_browser_test.h"
-#include "content/public/test/content_browser_test_utils.h"
 #include "content/public/test/test_utils.h"
 #include "content/public/test/url_loader_interceptor.h"
 #include "net/dns/mock_host_resolver.h"
@@ -57,9 +52,7 @@
 #include "services/network/public/cpp/features.h"
 #include "services/network/public/cpp/network_switches.h"
 #include "services/network/public/mojom/web_client_hints_types.mojom-shared.h"
-#include "testing/gmock/include/gmock/gmock-matchers.h"
 #include "testing/gmock/include/gmock/gmock.h"
-#include "third_party/abseil-cpp/absl/types/optional.h"
 #include "third_party/blink/public/common/client_hints/client_hints.h"
 #include "third_party/blink/public/common/web_preferences/web_preferences.h"
 
@@ -699,10 +692,8 @@ class ClientHintsBrowserTest : public InProcessBrowserTest,
         continue;
       }
 
-      // Skip over the `Sec-CH-UA-Reduced` client hint because it is only added
-      // in the presence of a valid "UserAgentReduction" Origin Trial token.
-      // `Sec-CH-UA-Reduced` is tested via UaReducedOriginTrialBrowserTest
-      // below.
+      // TODO(crbug.com/1226193): Remove this block when support for
+      // `Sec-CH-UA-Reduced` has been added.
       if (std::string(blink::kClientHintsHeaderMapping[i]) ==
           "sec-ch-ua-reduced") {
         continue;
@@ -2484,190 +2475,3 @@ IN_PROC_BROWSER_TEST_F(ClientHintsBrowserTestWithEmulatedMedia,
   ui_test_utils::NavigateToURL(browser(), test_url());
   EXPECT_EQ(prefers_color_scheme_observed(), "dark");
 }
-
-// Tests that the Sec-CH-UA-Reduced client hint is sent if and only if the
-// UserAgentReduction Origin Trial token is present and valid in the response
-// headers.
-//
-// The test Origin Trial token found in the test files was generated by running
-// (in tools/origin_trials):
-// generate_token.py https://127.0.0.1:44444 UserAgentReduction
-// --expire-timestamp=2000000000
-//
-// The Origin Trial token expires in 2033.  Generate a new token by then, or
-// find a better way to re-generate a test trial token.
-class UaReducedOriginTrialBrowserTest : public InProcessBrowserTest {
- public:
-  UaReducedOriginTrialBrowserTest()
-      : https_server_(net::EmbeddedTestServer::TYPE_HTTPS) {
-    https_server_.ServeFilesFromSourceDirectory(
-        "chrome/test/data/client_hints");
-    https_server_.RegisterRequestMonitor(base::BindRepeating(
-        &UaReducedOriginTrialBrowserTest::MonitorResourceRequest,
-        base::Unretained(this)));
-    // Always start the server on the same port, because Origin Trial tokens are
-    // bound to an origin (schema/host/port).
-    EXPECT_TRUE(https_server_.Start(/*port=*/44444));
-  }
-
-  void SetUpCommandLine(base::CommandLine* command_line) override {
-    // The public key for the default privatey key used by the
-    // tools/origin_trials/generate_token.py tool.
-    static constexpr char kOriginTrialTestPublicKey[] =
-        "dRCs+TocuKkocNKa0AtZ4awrt9XKH2SQCI6o4FY6BNA=";
-    command_line->AppendSwitchASCII(embedder_support::kOriginTrialPublicKey,
-                                    kOriginTrialTestPublicKey);
-  }
-
-  void SetUpOnMainThread() override {
-    host_resolver()->AddRule("*", "127.0.0.1");
-  }
-
-  static absl::optional<std::string> GetHeaderValue(
-      const net::test_server::HttpRequest& request,
-      const std::string& header) {
-    if (request.headers.find(header) != request.headers.end()) {
-      return request.headers.find(header)->second;
-    } else {
-      return absl::nullopt;
-    }
-  }
-
-  // Called by `https_server_`, as a callback when navigating to a URL and a
-  // request is about to be sent.
-  void MonitorResourceRequest(const net::test_server::HttpRequest& request) {
-    absl::optional<std::string> ua_reduced_value =
-        GetHeaderValue(request, "sec-ch-ua-reduced");
-    if (ua_reduced_value.has_value()) {
-      SetUaReducedClientHintValue(*ua_reduced_value);
-    } else {
-      ClearUaReducedClientHintValue();
-    }
-  }
-
-  absl::optional<std::string> UaReducedClientHintValue() {
-    base::AutoLock lock(ua_reduced_client_hint_value_mutex_);
-    return ua_reduced_client_hint_value_;
-  }
-
-  void SetUaReducedClientHintValue(const std::string& value) {
-    base::AutoLock lock(ua_reduced_client_hint_value_mutex_);
-    ua_reduced_client_hint_value_ = value;
-  }
-
-  void ClearUaReducedClientHintValue() {
-    base::AutoLock lock(ua_reduced_client_hint_value_mutex_);
-    ua_reduced_client_hint_value_.reset();
-  }
-
-  GURL ua_reduced_with_valid_origin_trial_token_url() const {
-    return https_server_.GetURL(
-        "/accept_ch_ua_reduced_with_valid_origin_trial.html");
-  }
-
-  GURL ua_reduced_with_invalid_origin_trial_token_url() const {
-    return https_server_.GetURL(
-        "/accept_ch_ua_reduced_with_invalid_origin_trial.html");
-  }
-
-  GURL ua_reduced_with_no_origin_trial_token_url() const {
-    return https_server_.GetURL(
-        "/accept_ch_ua_reduced_with_no_origin_trial.html");
-  }
-
-  GURL ua_reduced_missing_with_valid_origin_trial_token_url() const {
-    return https_server_.GetURL(
-        "/accept_ch_ua_reduced_missing_valid_origin_trial.html");
-  }
-
-  GURL critical_ch_ua_reduced_with_valid_origin_trial_token_url() const {
-    return https_server_.GetURL(
-        "/critical_ch_ua_reduced_with_valid_origin_trial.html");
-  }
-
-  GURL critical_ch_ua_reduced_with_invalid_origin_trial_token_url() const {
-    return https_server_.GetURL(
-        "/critical_ch_ua_reduced_with_invalid_origin_trial.html");
-  }
-
-  void NavigateTwiceWithoutCriticalCH(const GURL& url) {
-    // The first navigation is in order to set the Accept-CH cache with the
-    // client hints in the Accept-CH response header.
-    ui_test_utils::NavigateToURL(browser(), url);
-    // In the first navigation, the client hints should not be present.
-    EXPECT_THAT(UaReducedClientHintValue(), Eq(absl::nullopt));
-    // The next navigation is to inspect the request headers sent in subsequent
-    // requests.
-    ui_test_utils::NavigateToURL(browser(), url);
-  }
-
- private:
-  net::EmbeddedTestServer https_server_;
-  base::Lock ua_reduced_client_hint_value_mutex_;
-  // Guarded by a mutex because it's written to by the IO sequence and read from
-  // the main test execution thread.
-  absl::optional<std::string> ua_reduced_client_hint_value_
-      GUARDED_BY(ua_reduced_client_hint_value_mutex_);
-};
-
-IN_PROC_BROWSER_TEST_F(UaReducedOriginTrialBrowserTest,
-                       AcceptChUaReducedWithValidOriginTrialToken) {
-  NavigateTwiceWithoutCriticalCH(
-      ua_reduced_with_valid_origin_trial_token_url());
-
-  EXPECT_THAT(UaReducedClientHintValue(), Optional(Eq("?1")));
-}
-
-IN_PROC_BROWSER_TEST_F(UaReducedOriginTrialBrowserTest,
-                       AcceptChUaReducedWithInvalidOriginTrialToken) {
-  NavigateTwiceWithoutCriticalCH(
-      ua_reduced_with_invalid_origin_trial_token_url());
-
-  // The response contained Sec-CH-UA-Reduced in the Accept-CH header, but the
-  // origin trial token is invalid.
-  EXPECT_THAT(UaReducedClientHintValue(), Eq(absl::nullopt));
-}
-
-IN_PROC_BROWSER_TEST_F(UaReducedOriginTrialBrowserTest,
-                       AcceptChUaReducedWithNoOriginTrialToken) {
-  NavigateTwiceWithoutCriticalCH(ua_reduced_with_no_origin_trial_token_url());
-
-  // The response contained Sec-CH-UA-Reduced in the Accept-CH header, but the
-  // origin trial token is not present.
-  EXPECT_THAT(UaReducedClientHintValue(), Eq(absl::nullopt));
-}
-
-IN_PROC_BROWSER_TEST_F(UaReducedOriginTrialBrowserTest,
-                       NoAcceptChUaReducedWithValidOriginTrialToken) {
-  NavigateTwiceWithoutCriticalCH(
-      ua_reduced_missing_with_valid_origin_trial_token_url());
-
-  // The response contained a valid Origin Trial token, but no Sec-CH-UA-Reduced
-  // in the Accept-CH header.
-  EXPECT_THAT(UaReducedClientHintValue(), Eq(absl::nullopt));
-}
-
-IN_PROC_BROWSER_TEST_F(UaReducedOriginTrialBrowserTest,
-                       CriticalChUaReducedWithValidOriginTrialToken) {
-  ui_test_utils::NavigateToURL(
-      browser(), critical_ch_ua_reduced_with_valid_origin_trial_token_url());
-
-  // The initial navigation also contains the Critical-CH header, so the
-  // Sec-CH-UA-Reduced header should be set after the first navigation.
-  EXPECT_THAT(UaReducedClientHintValue(), Optional(Eq("?1")));
-}
-
-IN_PROC_BROWSER_TEST_F(UaReducedOriginTrialBrowserTest,
-                       CriticalChUaReducedWithInvalidOriginTrialToken) {
-  ui_test_utils::NavigateToURL(
-      browser(), critical_ch_ua_reduced_with_invalid_origin_trial_token_url());
-
-  // The Origin Trial token is invalid, so the Critical-CH should not have
-  // resulted in the Sec-CH-UA-Reduced header being sent.
-  EXPECT_THAT(UaReducedClientHintValue(), Eq(absl::nullopt));
-}
-
-IN_PROC_BROWSER_TEST_F(UaReducedOriginTrialBrowserTest,
-                       ThirdPartyUaReducedWithValidOriginTrialToken) {
-  // TODO(crbug.com/1222742): Implement this test.
-}