Remove Experimental Flag ExternalAppPromptDisabled

This was released a long time ago. Removing flag to clear clutter.

BUG=338334

Review-Url: https://codereview.chromium.org/2875153002
Cr-Commit-Position: refs/heads/master@{#471162}

ios/chrome/browser/experimental_flags.h

@@ -45,9 +45,6 @@ bool IsAlertOnBackgroundUploadEnabled();
 // Whether auto-reload is enabled.
 bool IsAutoReloadEnabled();
 
-// Whether the external applicaiton prompt is enabled.
-bool IsExternalApplicationPromptEnabled();
-
 // Whether contextual search must be reset to undecided state.
 bool IsForceResetContextualSearchEnabled();
 

ios/chrome/browser/experimental_flags.mm

@@ -33,7 +33,6 @@ NSString* const kEnableAlertOnBackgroundUpload =
 NSString* const kEnableNewClearBrowsingDataUI = @"EnableNewClearBrowsingDataUI";
 NSString* const kEnableStartupCrash = @"EnableStartupCrash";
 NSString* const kEnableViewCopyPasswords = @"EnableViewCopyPasswords";
-NSString* const kExternalAppPromptDisabled = @"ExternalAppPromptDisabled";
 NSString* const kFirstRunForceEnabled = @"FirstRunForceEnabled";
 NSString* const kForceResetContextualSearch = @"ForceResetContextualSearch";
 NSString* const kGaiaEnvironment = @"GAIAEnvironment";
@@ -99,11 +98,6 @@ bool IsAutoReloadEnabled() {
                           base::CompareCase::INSENSITIVE_ASCII);
 }
 
-bool IsExternalApplicationPromptEnabled() {
-  return ![[NSUserDefaults standardUserDefaults]
-      boolForKey:kExternalAppPromptDisabled];
-}
-
 bool IsForceResetContextualSearchEnabled() {
   return [[NSUserDefaults standardUserDefaults]
       boolForKey:kForceResetContextualSearch];

ios/chrome/browser/resources/Settings.bundle/Experimental.plist

@@ -374,16 +374,6 @@
 				<string>Enabled</string>
 			</array>
 		</dict>
-		<dict>
-			<key>Type</key>
-			<string>PSToggleSwitchSpecifier</string>
-			<key>Title</key>
-			<string>Disable External Application Prompt</string>
-			<key>Key</key>
-			<string>ExternalAppPromptDisabled</string>
-			<key>DefaultValue</key>
-			<false/>
-		</dict>
 		<dict>
 			<key>Type</key>
 			<string>PSToggleSwitchSpecifier</string>

ios/chrome/browser/web/external_app_launcher.mm

@@ -177,15 +177,13 @@ NSString* PromptActionString(NSString* scheme) {
       UIApplicationStateActive)
     return NO;
 
-  if (experimental_flags::IsExternalApplicationPromptEnabled()) {
-    // Prompt user to open itunes when opening it is not a result of a link
-    // click.
-    if (!linkClicked && UrlHasAppStoreScheme(gURL)) {
-      [self performSelector:@selector(openExternalAppWithPromptForURL:)
-                 withObject:URL
-                 afterDelay:0.0];
-      return YES;
-    }
+  // Prompt user to open itunes when opening it is not a result of a link
+  // click.
+  if (!linkClicked && UrlHasAppStoreScheme(gURL)) {
+    [self performSelector:@selector(openExternalAppWithPromptForURL:)
+               withObject:URL
+               afterDelay:0.0];
+    return YES;
   }
 
   // Replaces |URL| with a rewritten URL if it is of mailto: scheme.