[ios] Add more experimental policy

Enabling default search engine relevant policis to experimental settings.

Bug: 1108998
Change-Id: Ifa6bb13c981cea73ca989903a4fb8098d207a0b4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2327452Reviewed-by: sebsg <sebsg@chromium.org>
Commit-Queue: Tina Wang <tinazwang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#792932}

ios/chrome/browser/flags/about_flags.mm

@@ -720,6 +720,9 @@ void AppendSwitchesFromExperimentalSettings(base::CommandLine* command_line) {
       base::SysUTF8ToNSString(policy::key::kAutofillCreditCardEnabled),
       base::SysUTF8ToNSString(policy::key::kChromeVariations),
       base::SysUTF8ToNSString(policy::key::kDefaultPopupsSetting),
+      base::SysUTF8ToNSString(policy::key::kDefaultSearchProviderEnabled),
+      base::SysUTF8ToNSString(policy::key::kDefaultSearchProviderName),
+      base::SysUTF8ToNSString(policy::key::kDefaultSearchProviderSearchURL),
       base::SysUTF8ToNSString(policy::key::kPasswordManagerEnabled)
     ];
 
@@ -736,6 +739,14 @@ void AppendSwitchesFromExperimentalSettings(base::CommandLine* command_line) {
       // 2 = Do not allow any site to show popups
       base::SysUTF8ToNSString(policy::key::kDefaultPopupsSetting) : @2,
 
+      // Set default search engine.
+      base::SysUTF8ToNSString(policy::key::kDefaultSearchProviderEnabled) :
+          @YES,
+      base::SysUTF8ToNSString(policy::key::kDefaultSearchProviderSearchURL) :
+          @"http://www.google.com/search?q={searchTerms}",
+      base::SysUTF8ToNSString(policy::key::kDefaultSearchProviderName) :
+          @"Google",
+
       base::SysUTF8ToNSString(policy::key::kPasswordManagerEnabled) : @NO,
     };
     NSDictionary* registration_defaults =