[ios] Enables enterprise policy by default on non-stable channels.

Only enables the core policy infrastructure. The handlers that parse
policy data will remain disabled by default.

BUG=1024115

Change-Id: I57d38c44313a6b545353eb1f8c0d1a55b92a5e3e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2127946Reviewed-by: Mike Dougherty <michaeldo@chromium.org>
Commit-Queue: Rohit Rao <rohitrao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#755325}

ios/chrome/browser/policy/BUILD.gn

@@ -45,7 +45,9 @@ source_set("feature_flags") {
   ]
   deps = [
     "//base",
+    "//components/version_info",
     "//ios/chrome/browser:utils",
+    "//ios/chrome/common",
   ]
 }
 

ios/chrome/browser/policy/configuration_policy_handler_list_factory.mm

@@ -44,10 +44,13 @@ std::unique_ptr<policy::ConfigurationPolicyHandlerList> BuildPolicyHandlerList(
           base::Bind(&PopulatePolicyHandlerParameters),
           base::Bind(&policy::GetChromePolicyDetails));
 
-  for (size_t i = 0; i < base::size(kSimplePolicyMap); ++i) {
-    handlers->AddHandler(std::make_unique<SimplePolicyHandler>(
-        kSimplePolicyMap[i].policy_name, kSimplePolicyMap[i].preference_path,
-        kSimplePolicyMap[i].value_type));
+  // Check the feature flag before adding handlers to the list.
+  if (ShouldInstallEnterprisePolicyHandlers()) {
+    for (size_t i = 0; i < base::size(kSimplePolicyMap); ++i) {
+      handlers->AddHandler(std::make_unique<SimplePolicyHandler>(
+          kSimplePolicyMap[i].policy_name, kSimplePolicyMap[i].preference_path,
+          kSimplePolicyMap[i].value_type));
+    }
   }
 
   return handlers;

ios/chrome/browser/policy/policy_features.cc

@@ -5,12 +5,30 @@
 #include "ios/chrome/browser/policy/policy_features.h"
 
 #include "base/command_line.h"
+#include "components/version_info/version_info.h"
 #include "ios/chrome/browser/chrome_switches.h"
+#include "ios/chrome/common/channel_info.h"
 
-bool IsEnterprisePolicyEnabled() {
+namespace {
+
+// Returns true if the current command line contains the
+// |kEnableEnterprisePolicy| switch.
+bool IsEnableEnterprisePolicySwitchPresent() {
   // This feature is controlled via the command line because policy must be
   // initialized before about:flags or field trials. Using a command line flag
   // is the only way to control this feature at runtime.
   base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
   return command_line->HasSwitch(switches::kEnableEnterprisePolicy);
 }
+
+}  // namespace
+
+bool IsEnterprisePolicyEnabled() {
+  // Policy is enabled by default for non-stable channels.
+  return GetChannel() != version_info::Channel::STABLE ||
+         IsEnableEnterprisePolicySwitchPresent();
+}
+
+bool ShouldInstallEnterprisePolicyHandlers() {
+  return IsEnableEnterprisePolicySwitchPresent();
+}

ios/chrome/browser/policy/policy_features.h

@@ -5,7 +5,13 @@
 #ifndef IOS_CHROME_BROWSER_POLICY_POLICY_FEATURES_H_
 #define IOS_CHROME_BROWSER_POLICY_POLICY_FEATURES_H_
 
-// Returns true if enterprise policy support is enabled.
+// Returns true if the core enterprise policy infrastructure is enabled. Does
+// not control whether policy data is parsed and made user visible; that is
+// controlled by |ShouldInstallEnterprisePolicyHandlers()| below.
 bool IsEnterprisePolicyEnabled();
 
+// Returns true if enterprise policy handlers should be installed to parse
+// policy data and make it user visible.
+bool ShouldInstallEnterprisePolicyHandlers();
+
 #endif  // IOS_CHROME_BROWSER_POLICY_POLICY_FEATURES_H_