Implement a modal permission dialog on Android gated by a feature.

chrome/browser/BUILD.gn

Index: chrome/browser/BUILD.gn
diff --git a/chrome/browser/BUILD.gn b/chrome/browser/BUILD.gn
index d7473bf54f8cf901b430290209ef3af16eb9fffe..5200a6574106e1a7c0fb9b991f0b7bcbc61f999d 100644
--- a/chrome/browser/BUILD.gn
+++ b/chrome/browser/BUILD.gn
@@ -3309,6 +3309,8 @@ split_static_library("browser") {
       "password_manager/update_password_infobar_delegate_android.h",
       "permissions/grouped_permission_infobar_delegate_android.cc",
       "permissions/grouped_permission_infobar_delegate_android.h",
+      "permissions/permission_dialog_delegate.cc",
+      "permissions/permission_dialog_delegate.h",
       "permissions/permission_infobar_delegate.cc",
       "permissions/permission_infobar_delegate.h",
       "permissions/permission_prompt_android.cc",
@@ -3888,6 +3890,8 @@ if (android_java_ui) {
       "../android/java/src/org/chromium/chrome/browser/password_manager/AccountChooserDialog.java",
       "../android/java/src/org/chromium/chrome/browser/password_manager/AutoSigninFirstRunDialog.java",
       "../android/java/src/org/chromium/chrome/browser/password_manager/Credential.java",
+      "../android/java/src/org/chromium/chrome/browser/permissions/PermissionDialogController.java",
+      "../android/java/src/org/chromium/chrome/browser/permissions/PermissionDialogDelegate.java",
       "../android/java/src/org/chromium/chrome/browser/physicalweb/UrlManager.java",
       "../android/java/src/org/chromium/chrome/browser/policy/PolicyAuditor.java",
       "../android/java/src/org/chromium/chrome/browser/precache/PrecacheLauncher.java",