[Extensions UI] Initially disabled OK button for extension install prompts.

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

Index: chrome/browser/ui/views/extensions/extension_install_dialog_view.cc
diff --git a/chrome/browser/ui/views/extensions/extension_install_dialog_view.cc b/chrome/browser/ui/views/extensions/extension_install_dialog_view.cc
index 38f05c54b5bf1bf7ef0c1174cecf847ed174fff9..e36d5b66f5a7d315c54bc203cbd8168555966a25 100644
--- a/chrome/browser/ui/views/extensions/extension_install_dialog_view.cc
+++ b/chrome/browser/ui/views/extensions/extension_install_dialog_view.cc
@@ -51,6 +51,7 @@
 #include "ui/views/layout/box_layout.h"
 #include "ui/views/layout/grid_layout.h"
 #include "ui/views/widget/widget.h"
+#include "ui/views/window/dialog_client_view.h"
 
 using content::OpenURLParams;
 using content::Referrer;
@@ -90,6 +91,9 @@ int GetLeftPaddingForBulletedItems(bool parent_bulleted) {
          (parent_bulleted ? 2 : 1);
 }
 
+// Time delay before the install button is enabled after initial display.
+int g_install_delay_in_ms = 500;
+
 void AddResourceIcon(const gfx::ImageSkia* skia_image, void* data) {
   views::View* parent = static_cast<views::View*>(data);
   views::ImageView* image_view = new views::ImageView();
@@ -181,7 +185,8 @@ ExtensionInstallDialogView::ExtensionInstallDialogView(
       prompt_(std::move(prompt)),
       container_(NULL),
       scroll_view_(NULL),
-      handled_result_(false) {
+      handled_result_(false),
+      install_button_enabled_(false) {
   InitView();
 }
 
@@ -595,6 +600,35 @@ views::View* ExtensionInstallDialogView::CreateExtraView() {
   return store_link;
 }
 
+bool ExtensionInstallDialogView::IsDialogButtonEnabled(
+    ui::DialogButton button) const {
+  if (button == ui::DIALOG_BUTTON_OK)
+    return install_button_enabled_;
+  return true;
+}
+
+void ExtensionInstallDialogView::SetInstallButtonDelayForTesting(
+    int delay_in_ms) {
+  g_install_delay_in_ms = delay_in_ms;
+}
+
+void ExtensionInstallDialogView::VisibilityChanged(views::View* starting_from,
+                                                   bool is_visible) {
+  if (is_visible && !install_button_enabled_) {
+    // This base::Unretained is safe because the task is owned by the timer,
+    // which is in turn owned by this object.
+    timer_.Start(FROM_HERE,
+                 base::TimeDelta::FromMilliseconds(g_install_delay_in_ms),
+                 base::Bind(&ExtensionInstallDialogView::EnableInstallButton,
+                            base::Unretained(this)));
+  }
+}
+
+void ExtensionInstallDialogView::EnableInstallButton() {
+  install_button_enabled_ = true;
+  GetDialogClientView()->UpdateDialogButtons();
+}
+
 void ExtensionInstallDialogView::UpdateInstallResultHistogram(bool accepted)
     const {
   if (prompt_->type() == ExtensionInstallPrompt::INSTALL_PROMPT)