Fix extension scrollbar regression bug, and add a regression test to

chrome/browser/ui/views/extensions/extension_install_dialog_view_browsertest.cc

Index: chrome/browser/ui/views/extensions/extension_install_dialog_view_browsertest.cc
diff --git a/chrome/browser/ui/views/extensions/extension_install_dialog_view_browsertest.cc b/chrome/browser/ui/views/extensions/extension_install_dialog_view_browsertest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..2d5bf67a0a5acecea2cb48e01b1f679aabf57c69
--- /dev/null
+++ b/chrome/browser/ui/views/extensions/extension_install_dialog_view_browsertest.cc
@@ -0,0 +1,180 @@
+// Copyright 2014 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 "base/run_loop.h"
+#include "base/strings/utf_string_conversions.h"
+#include "chrome/browser/extensions/extension_browsertest.h"
+#include "chrome/browser/extensions/extension_icon_manager.h"
+#include "chrome/browser/extensions/extension_install_prompt.h"
+#include "chrome/browser/extensions/extension_install_prompt_experiment.h"
+#include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/tabs/tab_strip_model.h"
+#include "chrome/browser/ui/views/constrained_window_views.h"
+#include "chrome/browser/ui/views/extensions/extension_install_dialog_view.h"
+#include "chrome/browser/ui/webui/extensions/extension_settings_handler.h"
+#include "chrome/common/extensions/extension_test_util.h"
+#include "content/public/browser/browser_thread.h"
+#include "extensions/common/extension.h"
+#include "extensions/common/permissions/permissions_data.h"
+#include "extensions/common/test_util.h"
+#include "ui/views/controls/scroll_view.h"
+#include "ui/views/view.h"
+#include "ui/views/widget/widget.h"
+
+// A simple delegate implementation that counts the number of times
+// |InstallUIProceed| and |InstallUIAbort| are called.
+class MockExtensionInstallPromptDelegate
+    : public ExtensionInstallPrompt::Delegate {
+ public:
+  MockExtensionInstallPromptDelegate()
+      : proceed_count_(0),
+        abort_count_(0) {}
+
+  // ExtensionInstallPrompt::Delegate overrides.
+  virtual void InstallUIProceed() OVERRIDE;
+  virtual void InstallUIAbort(bool user_initiated) OVERRIDE;
+
+  int proceed_count() { return proceed_count_; }
+  int abort_count() { return abort_count_; }
+
+ protected:
+  int proceed_count_;
+  int abort_count_;
+};
+
+void MockExtensionInstallPromptDelegate::InstallUIProceed() {
+  ++proceed_count_;
+}
+
+void MockExtensionInstallPromptDelegate::InstallUIAbort(bool user_initiated) {
+  ++abort_count_;
+}
+
+// This lets us construct the parent for the prompt we're constructing in our
+// tests.
+class MockExtensionInstallPrompt : public ExtensionInstallPrompt {
+ public:
+  explicit MockExtensionInstallPrompt(content::WebContents* web_contents)
+      : ExtensionInstallPrompt(web_contents), prompt_(NULL) {}
+  virtual ~MockExtensionInstallPrompt() {}
+  void set_prompt(ExtensionInstallPrompt::Prompt* prompt) {
+    prompt_ = prompt;
+  }
+  ExtensionInstallPrompt::Prompt* get_prompt() {
+    return prompt_;
+  }
+
+ private:
+  ExtensionInstallPrompt::Prompt* prompt_;
+};
+
+class ScrollbarTest : public ExtensionBrowserTest {
+ protected:
+  ScrollbarTest();
+  virtual ~ScrollbarTest() {}
+
+  virtual void SetUpOnMainThread() OVERRIDE;
+
+  void SetPromptPermissions(std::vector<base::string16> permissions);
+  void SetPromptDetails(std::vector<base::string16> details);
+  void SetPromptRetainedFiles(std::vector<base::FilePath> files);
+
+  bool IsScrollbarVisible();
+
+ private:
+  const extensions::Extension* extension_;
+  MockExtensionInstallPrompt* install_prompt_;
+  scoped_refptr<ExtensionInstallPrompt::Prompt> prompt_;
+  content::WebContents* web_contents_;
+};
+
+ScrollbarTest::ScrollbarTest() :
+  extension_(NULL),
+  install_prompt_(NULL),
+  prompt_(new ExtensionInstallPrompt::Prompt(
+      ExtensionInstallPrompt::PERMISSIONS_PROMPT)),
+  web_contents_(NULL) {}
+
+void ScrollbarTest::SetUpOnMainThread() {
+  ExtensionBrowserTest::SetUpOnMainThread();
+  extension_ = ExtensionBrowserTest::LoadExtension(test_data_dir_.AppendASCII(
+      "install_prompt/permissions_scrollbar_regression"));
+
+  web_contents_ = browser()->tab_strip_model()->GetWebContentsAt(0);
+
+  install_prompt_ = new MockExtensionInstallPrompt(web_contents_);
+  install_prompt_->set_prompt(prompt_);
+  prompt_->set_experiment(ExtensionInstallPromptExperiment::ControlGroup());
+  prompt_->set_extension(extension_);
+
+  scoped_ptr<ExtensionIconManager> icon_manager(new ExtensionIconManager());
+  const SkBitmap icon_bitmap = icon_manager->GetIcon(extension_->id());
+  gfx::Image icon = gfx::Image::CreateFrom1xBitmap(icon_bitmap);
+  prompt_->set_icon(icon);
+
+  this->SetPromptPermissions(std::vector<base::string16>());
+  this->SetPromptDetails(std::vector<base::string16>());
+  this->SetPromptRetainedFiles(std::vector<base::FilePath>());
+}
+
+void ScrollbarTest::SetPromptPermissions(
+    std::vector<base::string16> permissions) {
+  prompt_->SetPermissions(permissions);
+}
+
+void ScrollbarTest::SetPromptDetails(
+    std::vector<base::string16> details) {
+  prompt_->SetPermissionsDetails(details);
+}
+
+void ScrollbarTest::SetPromptRetainedFiles(
+    std::vector<base::FilePath> files) {
+  prompt_->set_retained_files(files);
+}
+
+bool ScrollbarTest::IsScrollbarVisible() {
+  ExtensionInstallPrompt::ShowParams show_params(web_contents_);
+  MockExtensionInstallPromptDelegate delegate;
+  ExtensionInstallDialogView* dialog =
+      new ExtensionInstallDialogView(show_params.navigator, &delegate, prompt_);
+
+  // Create the modal view around the install dialog view.
+  views::Widget* modal =
+      CreateBrowserModalDialogViews(dialog, show_params.parent_window);
+  modal->Show();
+  content::BrowserThread::GetBlockingPool()->FlushForTesting();
+  base::RunLoop().RunUntilIdle();
+
+  // Check if the vertical scrollbar is visible.
+  return dialog->scroll_view()->vertical_scroll_bar()->visible();
+}
+
+// Tests that a scrollbar _is_ shown for an excessively long extension
+// install prompt.
+IN_PROC_BROWSER_TEST_F(ScrollbarTest, LongPromptScrollbar) {
+  base::string16 permission_string(base::ASCIIToUTF16("Test"));
+  std::vector<base::string16> permissions;
+  std::vector<base::string16> details;
+  for (int i = 0; i < 20; i++) {
+    permissions.push_back(permission_string);
+    details.push_back(base::string16());
+  }
+  this->SetPromptPermissions(permissions);
+  this->SetPromptDetails(details);
+  ASSERT_TRUE(IsScrollbarVisible()) << "Scrollbar is not visible";
+}
+
+// Tests that a scrollbar isn't shown for this regression case.
+// See crbug.com/385570 for details.
+IN_PROC_BROWSER_TEST_F(ScrollbarTest, ScrollbarRegression) {
+  base::string16 permission_string(base::ASCIIToUTF16(
+      "Read and modify your data on *.facebook.com"));
+  std::vector<base::string16> permissions;
+  permissions.push_back(permission_string);
+  this->SetPromptPermissions(permissions);
+  std::vector<base::string16> details;
+  details.push_back(base::string16());
+  this->SetPromptDetails(details);
+  ASSERT_FALSE(IsScrollbarVisible()) << "Scrollbar is visible";
+}