Fix Account Manager's Add Account modal dimensions

The current dimensions sometimes cause the Chrome OS Account Manager's
account addition modal to overflow the screen.

Bug: 944186
Change-Id: I7960863e9b40c39a40151dc07c12fec193661382
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1539998Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Kush Sinha <sinhak@chromium.org>
Cr-Commit-Position: refs/heads/master@{#645358}

chrome/browser/ui/webui/chromeos/system_web_dialog_delegate.h

@@ -73,6 +73,9 @@ class SystemWebDialogDelegate : public ui::WebDialogDelegate {
 
  protected:
   FRIEND_TEST_ALL_PREFIXES(SystemWebDialogLoginTest, NonModalTest);
+
+  // Returns the dialog window (pointer to |aura::Window|). This will be a
+  // |nullptr| if the dialog has not been created yet.
   gfx::NativeWindow dialog_window() const { return dialog_window_; }
 
  private:
@@ -80,7 +83,7 @@ class SystemWebDialogDelegate : public ui::WebDialogDelegate {
   base::string16 title_;
   content::WebUI* webui_ = nullptr;
   ui::ModalType modal_type_;
-  gfx::NativeWindow dialog_window_;
+  gfx::NativeWindow dialog_window_ = nullptr;
 
   DISALLOW_COPY_AND_ASSIGN(SystemWebDialogDelegate);
 };

chrome/browser/ui/webui/signin/inline_login_handler_dialog_chromeos.cc

@@ -4,6 +4,7 @@
 
 #include "chrome/browser/ui/webui/signin/inline_login_handler_dialog_chromeos.h"
 
+#include <algorithm>
 #include <string>
 
 #include "base/logging.h"
@@ -12,6 +13,8 @@
 #include "chrome/common/webui_url_constants.h"
 #include "net/base/url_util.h"
 #include "ui/aura/window.h"
+#include "ui/display/display.h"
+#include "ui/display/screen.h"
 #include "url/gurl.h"
 
 namespace chromeos {
@@ -19,6 +22,8 @@ namespace chromeos {
 namespace {
 
 InlineLoginHandlerDialogChromeOS* dialog = nullptr;
+constexpr int kSigninDialogWidth = 768;
+constexpr int kSigninDialogHeight = 640;
 
 }  // namespace
 
@@ -49,6 +54,13 @@ InlineLoginHandlerDialogChromeOS::~InlineLoginHandlerDialogChromeOS() {
   dialog = nullptr;
 }
 
+void InlineLoginHandlerDialogChromeOS::GetDialogSize(gfx::Size* size) const {
+  const display::Display display =
+      display::Screen::GetScreen()->GetDisplayNearestWindow(dialog_window());
+  size->SetSize(std::min(kSigninDialogWidth, display.work_area().width()),
+                std::min(kSigninDialogHeight, display.work_area().height()));
+}
+
 std::string InlineLoginHandlerDialogChromeOS::GetDialogArgs() const {
   return std::string();
 }
@@ -57,10 +69,4 @@ bool InlineLoginHandlerDialogChromeOS::ShouldShowDialogTitle() const {
   return false;
 }
 
-void InlineLoginHandlerDialogChromeOS::GetDialogSize(gfx::Size* size) const {
-  constexpr int kSigninDialogWidth = 800;
-  constexpr int kSigninDialogHeight = 700;
-  size->SetSize(kSigninDialogWidth, kSigninDialogHeight);
-}
-
 }  // namespace chromeos