Add new desktop policy to control audio/video autoplay.

The "media.autoplay_allowed" preference can be set to allow autoplay as
a Chrome Policy. It is meant to be used for internal websites that may
be broken by the change described at chromium.org/audio-video/autoplay.

Bug: 779087, 819234
Change-Id: I6a2b5a13e80adfc72056536bc9cf425e30f50e6a
Reviewed-on: https://chromium-review.googlesource.com/941956
Commit-Queue: François Beaufort <beaufort.francois@gmail.com>
Reviewed-by: Julian Pastarmov <pastarmovj@chromium.org>
Reviewed-by: Mounir Lamouri <mlamouri@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#540805}(cherry picked from commit 4f8107d)
Reviewed-on: https://chromium-review.googlesource.com/951943
Reviewed-by: François Beaufort <beaufort.francois@gmail.com>
Cr-Commit-Position: refs/branch-heads/3359@{#68}
Cr-Branched-From: 66afc5e-refs/heads/master@{#540276}

Author: beaufortfrancois

chrome/browser/chrome_content_browser_client.cc

@@ -891,6 +891,9 @@ void ChromeContentBrowserClient::RegisterProfilePrefs(
   // used for mapping the command-line flags).
   registry->RegisterStringPref(prefs::kIsolateOrigins, std::string());
   registry->RegisterBooleanPref(prefs::kSitePerProcess, false);
+#if !defined(OS_ANDROID)
+  registry->RegisterBooleanPref(prefs::kAutoplayAllowed, false);
+#endif
 }
 
 // static
@@ -2750,6 +2753,14 @@ void ChromeContentBrowserClient::OverrideWebkitPrefs(
     }
   }
 
+#if !defined(OS_ANDROID)
+  if (prefs->GetBoolean(prefs::kAutoplayAllowed) &&
+      prefs->IsManagedPreference(prefs::kAutoplayAllowed)) {
+    web_prefs->autoplay_policy =
+        content::AutoplayPolicy::kNoUserGestureRequired;
+  }
+#endif  // !defined(OS_ANDROID)
+
   for (size_t i = 0; i < extra_parts_.size(); ++i)
     extra_parts_[i]->OverrideWebkitPrefs(rvh, web_prefs);
 }

chrome/browser/policy/configuration_policy_handler_list_factory.cc

@@ -774,6 +774,12 @@ const PolicyToPreferenceMapEntry kSimplePolicyMap[] = {
     prefs::kRelaunchNotificationPeriod,
     base::Value::Type::INTEGER },
 #endif  // !defined(OS_ANDROID)
+
+#if !defined(OS_ANDROID)
+  { key::kAutoplayAllowed,
+    prefs::kAutoplayAllowed,
+    base::Value::Type::BOOLEAN },
+#endif  // !defined(OS_ANDROID)
 };
 // clang-format on
 

chrome/browser/policy/policy_browsertest.cc

@@ -158,6 +158,7 @@
 #include "content/public/common/content_switches.h"
 #include "content/public/common/result_codes.h"
 #include "content/public/common/url_constants.h"
+#include "content/public/common/web_preferences.h"
 #include "content/public/test/browser_test_utils.h"
 #include "content/public/test/download_test_observer.h"
 #include "content/public/test/mock_notification_observer.h"
@@ -5045,4 +5046,31 @@ IN_PROC_BROWSER_TEST_F(NoteTakingOnLockScreenPolicyTest,
 
 #endif  // defined(OS_CHROMEOS)
 
+#if !defined(OS_ANDROID)
+
+IN_PROC_BROWSER_TEST_F(PolicyTest, AutoplayAllowedByPolicy) {
+  ASSERT_TRUE(embedded_test_server()->Start());
+  content::WebContents* web_contents =
+      browser()->tab_strip_model()->GetActiveWebContents();
+
+  // Check that autoplay was not allowed.
+  EXPECT_EQ(
+      web_contents->GetRenderViewHost()->GetWebkitPreferences().autoplay_policy,
+      content::AutoplayPolicy::kDocumentUserActivationRequired);
+
+  // Update policy to allow autoplay.
+  PolicyMap policies;
+  SetPolicy(&policies, key::kAutoplayAllowed,
+            std::make_unique<base::Value>(true));
+  UpdateProviderPolicy(policies);
+
+  // Check that autoplay was allowed by policy.
+  web_contents->GetRenderViewHost()->OnWebkitPreferencesChanged();
+  EXPECT_EQ(
+      web_contents->GetRenderViewHost()->GetWebkitPreferences().autoplay_policy,
+      content::AutoplayPolicy::kNoUserGestureRequired);
+}
+
+#endif  // !defined(OS_ANDROID)
+
 }  // namespace policy

chrome/common/pref_names.cc

@@ -2568,4 +2568,9 @@ const char kSitePerProcess[] = "site_isolation.site_per_process";
 const char kWebDriverOverridesIncompatiblePolicies[] =
     "webdriver.override_incompatible_policy";
 
+#if !defined(OS_ANDROID)
+// Boolean that specifies whether media (audio/video) autoplay is allowed.
+const char kAutoplayAllowed[] = "media.autoplay_allowed";
+#endif  // !defined(OS_ANDROID)
+
 }  // namespace prefs

chrome/common/pref_names.h

@@ -919,6 +919,10 @@ extern const char kIsolateOrigins[];
 extern const char kSitePerProcess[];
 extern const char kWebDriverOverridesIncompatiblePolicies[];
 
+#if !defined(OS_ANDROID)
+extern const char kAutoplayAllowed[];
+#endif
+
 }  // namespace prefs
 
 #endif  // CHROME_COMMON_PREF_NAMES_H_

chrome/test/data/media/unified_autoplay.html

@@ -1,7 +1,7 @@
 <!DOCTYPE html>
 <html>
 <meta charset='utf-8'>
-<title>Simple autopaly test page</title>
+<title>Simple autoplay test page</title>
 <video src='bigbuck.webm'></video>
 <script>
 function attemptPlay() {

chrome/test/data/policy/policy_test_cases.json

@@ -3623,6 +3623,14 @@
     ]
   },
 
+  "AutoplayAllowed": {
+    "os": ["win", "linux", "mac", "chromeos"],
+    "test_policy": { "AutoplayAllowed": false },
+    "pref_mappings": [
+      { "pref": "media.autoplay_allowed" }
+    ]
+  },
+
   "----- Chrome Frame policies -------------------------------------------": {},
 
   "ChromeFrameRendererSettings": {

components/policy/resources/policy_templates.json

@@ -146,7 +146,7 @@
 #   persistent IDs for all fields (but not for groups!) are needed. These are
 #   specified by the 'id' keys of each policy. NEVER CHANGE EXISTING IDs,
 #   because doing so would break the deployed wire format!
-#   For your editing convenience: highest ID currently used: 429
+#   For your editing convenience: highest ID currently used: 430
 #   And don't forget to also update the EnterprisePolicies enum of
 #   histograms.xml (run 'python tools/metrics/histograms/update_policies.py').
 #
@@ -11481,6 +11481,28 @@
         If this policy is set, <ph name="PRODUCT_NAME">$1<ex>Google Chrome</ex></ph> will try to register itself and apply associated cloud policy for all profiles.
 
         The value of this policy is an Enrollment token that can be retrieved from the Google Admin console.''',
+    },
+    {
+      'name': 'AutoplayAllowed',
+      'type': 'main',
+      'schema': { 'type': 'boolean' },
+      'supported_on': ['chrome.win:66-', 'chrome.linux:66-', 'chrome.mac:66-', 'chrome_os:66-'],
+      'features': {
+        'dynamic_refresh': True,
+        'per_profile': True,
+      },
+      'example_value': True,
+      'id': 430,
+      'caption': '''Allows media autoplay''',
+      'tags': [],
+      'desc': '''Allows you to control if videos can play automatically (without user consent) with audio content in <ph name="PRODUCT_NAME">$1<ex>Google Chrome</ex></ph>.
+
+      If the policy is set to True, <ph name="PRODUCT_NAME">$1<ex>Google Chrome</ex></ph> is allowed to autoplay media.
+      If the policy is set to False, <ph name="PRODUCT_NAME">$1<ex>Google Chrome</ex></ph> is not allowed to autoplay media.
+      By default, <ph name="PRODUCT_NAME">$1<ex>Google Chrome</ex></ph> is not allowed to autoplay media.
+
+      Note that if <ph name="PRODUCT_NAME">$1<ex>Google Chrome</ex></ph> is running and this policy changes, it will be applied only to new opened tabs. Therefore some tabs might still observe the previous behavior.
+      ''',
     }
   ],
 

tools/metrics/histograms/enums.xml

@@ -12617,6 +12617,7 @@ Called by update_net_error_codes.py.-->
   <int value="427" label="DeviceRollbackToTargetVersion"/>
   <int value="428" label="MachineLevelUserCloudPolicyEnrollmentToken"/>
   <int value="429" label="SafeBrowsingExtendedReportingEnabled"/>
+  <int value="430" label="AutoplayAllowed"/>
 </enum>
 
 <enum name="EnterprisePolicyInvalidations">