[iOS] Move OverlayCoordinatorFactory initializer to category.

This allows for tests to create OverlayCoordinatorFactories for a
subset of OverlayRequest types for a given modality, allowing more
granular tests without duplicating OverlayCoordinatorFactory logic.

Bug: 941745
Change-Id: Icbf39e968eeb9e0d0814cad7e37b111e772e1de5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1636591
Commit-Queue: Kurt Horimoto <kkhorimoto@chromium.org>
Reviewed-by: Mike Dougherty <michaeldo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#664915}

ios/chrome/browser/ui/overlays/BUILD.gn

@@ -9,6 +9,7 @@ source_set("overlays") {
   ]
   sources = [
     "overlay_container_coordinator.mm",
+    "overlay_coordinator_factory+initialization.h",
     "overlay_coordinator_factory.mm",
     "overlay_presenter_ui_delegate_impl.h",
     "overlay_presenter_ui_delegate_impl.mm",

ios/chrome/browser/ui/overlays/overlay_coordinator_factory+initialization.h

+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef IOS_CHROME_BROWSER_UI_OVERLAYS_OVERLAY_COORDINATOR_FACTORY_INITIALIZATION_H_
+#define IOS_CHROME_BROWSER_UI_OVERLAYS_OVERLAY_COORDINATOR_FACTORY_INITIALIZATION_H_
+
+#import "ios/chrome/browser/ui/overlays/overlay_coordinator_factory.h"
+
+@interface OverlayRequestCoordinatorFactory (Initialization)
+// Initializer for a factory that supports the OverlayRequestCoordinator types
+// in |supportedOverlayClasses|.
+- (instancetype)initWithBrowser:(Browser*)browser
+    supportedOverlayRequestCoordinatorClasses:
+        (NSArray<Class>*)supportedOverlayClasses;
+@end
+
+#endif  // IOS_CHROME_BROWSER_UI_OVERLAYS_OVERLAY_COORDINATOR_FACTORY_INITIALIZATION_H_

ios/chrome/browser/ui/overlays/overlay_coordinator_factory.mm

@@ -5,6 +5,7 @@
 #import "ios/chrome/browser/ui/overlays/overlay_coordinator_factory.h"
 
 #include "base/logging.h"
+#import "ios/chrome/browser/ui/overlays/overlay_coordinator_factory+initialization.h"
 #import "ios/chrome/browser/ui/overlays/overlay_request_coordinator.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
@@ -18,10 +19,6 @@
 // associated with this coordinator factory.
 @property(nonatomic, readonly)
     NSArray<Class>* supportedOverlayRequestCoordinatorClasses;
-// Initializer used by |+factoryForBrowser:modality:|.
-- (instancetype)initWithBrowser:(Browser*)browser
-    supportedOverlayRequestCoordinatorClasses:
-        (NSArray<Class>*)supportedOverlayClasses NS_DESIGNATED_INITIALIZER;
 @end
 
 @implementation OverlayRequestCoordinatorFactory
@@ -40,18 +37,6 @@
       supportedOverlayRequestCoordinatorClasses:supportedCoordinatorClasses];
 }
 
-- (instancetype)initWithBrowser:(Browser*)browser
-    supportedOverlayRequestCoordinatorClasses:
-        (NSArray<Class>*)supportedOverlayClasses {
-  if (self = [super init]) {
-    _browser = browser;
-    DCHECK(_browser);
-    _supportedOverlayRequestCoordinatorClasses = supportedOverlayClasses;
-    DCHECK(_supportedOverlayRequestCoordinatorClasses.count);
-  }
-  return self;
-}
-
 - (OverlayRequestCoordinator*)
     newCoordinatorForRequest:(OverlayRequest*)request
            dismissalDelegate:(OverlayUIDismissalDelegate*)dismissalDelegate
@@ -71,3 +56,19 @@
 }
 
 @end
+
+@implementation OverlayRequestCoordinatorFactory (Initialization)
+
+- (instancetype)initWithBrowser:(Browser*)browser
+    supportedOverlayRequestCoordinatorClasses:
+        (NSArray<Class>*)supportedOverlayClasses {
+  if (self = [super init]) {
+    _browser = browser;
+    DCHECK(_browser);
+    _supportedOverlayRequestCoordinatorClasses = supportedOverlayClasses;
+    DCHECK(_supportedOverlayRequestCoordinatorClasses.count);
+  }
+  return self;
+}
+
+@end