[ios] Adds support for Find in Page to the new architecture.

ios/clean/chrome/browser/ui/find_in_page/find_in_page_coordinator.mm

Index: ios/clean/chrome/browser/ui/find_in_page/find_in_page_coordinator.mm
diff --git a/ios/clean/chrome/browser/ui/find_in_page/find_in_page_coordinator.mm b/ios/clean/chrome/browser/ui/find_in_page/find_in_page_coordinator.mm
new file mode 100644
index 0000000000000000000000000000000000000000..01362b3198e9a1ef0dd8c5e02733d87971420d60
--- /dev/null
+++ b/ios/clean/chrome/browser/ui/find_in_page/find_in_page_coordinator.mm
@@ -0,0 +1,107 @@
+// Copyright 2017 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.
+
+#import "ios/clean/chrome/browser/ui/find_in_page/find_in_page_coordinator.h"
+
+#include <memory>
+
+#include "base/logging.h"
+#import "ios/chrome/browser/find_in_page/find_tab_helper.h"
+#import "ios/clean/chrome/browser/ui/commands/find_in_page_visibility_commands.h"
+#import "ios/clean/chrome/browser/ui/find_in_page/find_in_page_mediator.h"
+#import "ios/clean/chrome/browser/ui/find_in_page/find_in_page_view_controller.h"
+#include "ios/shared/chrome/browser/tabs/web_state_list.h"
+#import "ios/shared/chrome/browser/ui/browser_list/browser.h"
+#import "ios/shared/chrome/browser/ui/commands/command_dispatcher.h"
+#import "ios/shared/chrome/browser/ui/coordinators/browser_coordinator+internal.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+@interface FindInPageCoordinator ()<FindInPageVisibilityCommands,
+                                    FindInPageConsumerProvider>
+
+@property(nonatomic, strong) FindInPageMediator* mediator;
+
+@property(nonatomic, strong)
+    FindInPageViewController* viewController;
+
+@end
+
+@implementation FindInPageCoordinator
+
+@synthesize mediator = _mediator;
+@synthesize viewController = _viewController;
+
+#pragma mark - Coordinator lifecycle management
+
+- (void)dealloc {
+  // TODO(rohitrao): The __weak pointers in the CommandDispatcher appear to have
+  // already been zeroed out by this point, so stopDispatchingToTarget:self does
+  // not appear to properly delete the forwarding entries for this target.  Work
+  // around this by calling stopDispatchingForSelector: instead.
+
+  CommandDispatcher* dispatcher = self.browser->dispatcher();
+  [dispatcher stopDispatchingForSelector:@selector(showFindInPage)];
+  [dispatcher stopDispatchingForSelector:@selector(hideFindInPage)];
+}
+
+- (void)wasAddedToParentCoordinator:(BrowserCoordinator*)parent {
+  DCHECK(self.browser);
+
+  // Register command handlers with the dispatcher.
+  CommandDispatcher* dispatcher = self.browser->dispatcher();
+  [dispatcher startDispatchingToTarget:self
+                           forSelector:@selector(showFindInPage)];
+  [dispatcher startDispatchingToTarget:self
+                           forSelector:@selector(hideFindInPage)];
+
+
+  _mediator = [[FindInPageMediator alloc] initWithWebStateList:(&self.browser->web_state_list()) provider:self dispatcher:static_cast<id>(dispatcher)];
+}
+
+- (void)wasRemovedFromParentCoordinator {
+  [self.browser->dispatcher() stopDispatchingToTarget:self];
+}
+
+- (void)start {
+  self.viewController = [[FindInPageViewController alloc] init];
+  self.viewController.dispatcher = static_cast<id>(self.browser->dispatcher());
+  [super start];
+}
+
+- (void)stop {
+  [super stop];
+  self.viewController = nil;
+}
+
+#pragma mark - Consumer provider
+
+- (id<FindInPageConsumer>)consumer {
+  if (!self.started) {
+    [self start];
+  }
+  DCHECK(self.viewController);
+  return self.viewController;
+}
+
+#pragma mark - Command handlers
+
+- (void)showFindInPage {
+  NSLog(@"showFindInPage command handler");

[marq (ping after 24h), 2017/04/06 16:13:27]

Remove logging.

[rohitrao (ping after 24h), 2017/04/11 20:46:16]

Done.

+  if (!self.started)
+    [self start];
+}
+
+- (void)hideFindInPage {
+  NSLog(@"hideFindInPage command handler");
+  web::WebState* webState = self.browser->web_state_list().GetActiveWebState();
+  FindTabHelper* helper = FindTabHelper::FromWebState(webState);

[marq (ping after 24h), 2017/04/06 16:13:27]

Feels like the mediator should be doing this part.

[rohitrao (ping after 24h), 2017/04/06 16:27:07]

Agreed, but I couldn't figure out how to push this into the mediator.

If I moved this into the mediator, how would the mediator cause the UI to be
closed?  We could use the dispatcher for that, but then we'd have both a
"public" hideFindInPage command as well as an "internal" noReallyCloseTheUINow
command, which I don't like.

[marq (ping after 24h), 2017/04/07 09:45:55]

Would just replacing lines 100-102 with [self.mediator stopFinding] be horrible?
That keeps the coordinator from caring about the internals of how FIP works, but
it retains the responsibility for catching commands and bossing the view
controller around.

[rohitrao (ping after 24h), 2017/04/11 20:46:16]

Done, at the cost of a larger public API for the mediator.

+  helper->StopFinding(nil);
+  if (self.started)
+    [self stop];
+}
+
+@end