Fix sizing issues in the tab modal signin flow.

chrome/browser/ui/signin_view_controller_delegate.cc

 // Copyright 2016 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.
 
 #include "chrome/browser/ui/signin_view_controller_delegate.h"
 
 #include "base/bind.h"
+#include "base/values.h"
 #include "chrome/browser/ui/signin_view_controller.h"
 #include "chrome/browser/ui/webui/signin/get_auth_frame.h"
 #include "content/public/browser/web_contents.h"
 
 namespace {
 
 content::WebContents* GetAuthFrameWebContents(
     content::WebContents* web_ui_web_contents) {
   return signin::GetAuthFrameWebContents(web_ui_web_contents, "signin-frame");
 }
 
 }  // namespace
 
 SigninViewControllerDelegate::SigninViewControllerDelegate(
     SigninViewController* signin_view_controller,
     content::WebContents* web_contents)
     : signin_view_controller_(signin_view_controller),
       web_contents_(web_contents) {
   web_contents_->SetDelegate(this);
   web_contents_->GetWebUI()->RegisterMessageCallback(

[Dan Beam, 2016/03/18 18:10:08]

hmmm, this is kind of weird.  I wonder why RegisterMessageCallback() is even
public.  this should probably be done from the webui or its handlers.

[anthonyvd, 2016/03/18 18:53:40]

Is there a canonical way to get this information from the handlers back to here,
where I can control the native views/windows?

[Dan Beam, 2016/03/18 21:07:47]

overall: I think it's just more common to handle messages... in "message
handlers", especially when one already exists for this webui:
https://code.google.com/p/chromium/codesearch#chromium/src/chrome/browser/ui/...

re: your question of "how does the handler access the delegate?"

if we either followed this precedent:
https://code.google.com/p/chromium/codesearch#chromium/src/chrome/browser/ui/...

  SigninViewController* ResizeSigninNativeView(int height) {
    signin_view_controller_.ResizeNativeView(height);
    // or signin_view_controller->delegate()->ResizeNativeView(height);
  }

or instead of mirroring the API, exposed a mutable pointer to the controller:

  SigninViewController* sign_in_view_controller() {
    return &sign_in_view_controller_;
  }

and did the same thing in the controller:
https://code.google.com/p/chromium/codesearch#chromium/src/chrome/browser/ui/...

either by creating a passthrough to that specific methods (copying API):

  void SigninViewController::ResizeNativeView(int height) {
    signin_view_controller_delegate_->ResizeNativeView(height);
  }

or by exposing the delegate:

  SigninViewControllerDelegate* signin_view_controller_delegate() {
    return signin_view_controller_delegate_;
  }

the handler could would look like:

  void SyncConfirmationHandler::HandleResizeNativeView(
      const base::ListValue* args) {
    double height_arg;
    bool success = args->GetDouble(0, &height_arg);
    DCHECK(success);

    Browser* browser = GetDesktopBrowser();
    int height = static_cast<int>(height_arg);

    // any of these
    browser->ResizeSigninNativeView(height);
    browser->sign_in_view_controller()->ResizeNativeView(height);
    browser->sign_in_view_controller()->delegate()->ResizeNativeView(height);
}

[anthonyvd, 2016/04/04 14:15:56]

Thanks for the detailed input. I wasn't too sure what was preferred between
having handlers in a non-webui-handler class vs exposing browser member
variables.

I went with exposing the view controller and its delegate. Let me know how this
looks!

       "navigationButtonClicked",
       base::Bind(&SigninViewControllerDelegate::HandleNavigationButtonClicked,
                  base::Unretained(this)));
+  web_contents_->GetWebUI()->RegisterMessageCallback(
+      "resizeNativeView",
+      base::Bind(&SigninViewControllerDelegate::HandleResizeNativeView,
+                 base::Unretained(this)));
 }
 
 SigninViewControllerDelegate::~SigninViewControllerDelegate() {}
 
 void SigninViewControllerDelegate::CloseModalSignin() {
   ResetSigninViewControllerDelegate();
   PerformClose();
 }
 
 void SigninViewControllerDelegate::ResetSigninViewControllerDelegate() {
@@ skipping 21 matching lines @@
 
 void SigninViewControllerDelegate::HandleNavigationButtonClicked(
     const base::ListValue* args) {
   if (CanGoBack(web_contents_)) {
     auto auth_web_contents = GetAuthFrameWebContents(web_contents_);
     auth_web_contents->GetController().GoBack();
   } else {
     CloseModalSignin();
   }
 }
+
+void SigninViewControllerDelegate::HandleResizeNativeView(
+    const base::ListValue* args) {
+  int height;
+  if (args->GetInteger(0, &height)) {

[Dan Beam, 2016/03/18 18:10:08]

double height;
CHECK(args->GetInteger(0, &height));
ResizeNativeView(static_cast<int>(height));

or

double height;
bool success = args->GetInteger(0, &height);
DCHECK(success);
ResizeNativeView(static_cast<int>(height));

[anthonyvd, 2016/03/18 18:53:40]

Done.

+    ResizeNativeView(height);
+  }
+}