[HBD] Add an Enable Flash context menu item for HBD placeholders.

chrome/renderer/plugins/chrome_plugin_placeholder.cc

Index: chrome/renderer/plugins/chrome_plugin_placeholder.cc
diff --git a/chrome/renderer/plugins/chrome_plugin_placeholder.cc b/chrome/renderer/plugins/chrome_plugin_placeholder.cc
index c40e8e47dea5cee9aa67f0a231ab56c286af30b8..dce392ed27b6a83ee5d83b8b4daa83023b110e21 100644
--- a/chrome/renderer/plugins/chrome_plugin_placeholder.cc
+++ b/chrome/renderer/plugins/chrome_plugin_placeholder.cc
@@ -313,6 +313,10 @@ void ChromePluginPlaceholder::OnMenuAction(int request_id, unsigned action) {
       HidePlugin();
       break;
     }
+    case chrome::MENU_COMMAND_ENABLE_FLASH: {
+      ShowPermissionBubbleCallback();
+      break;
+    }
     default:
       NOTREACHED();
   }
@@ -345,7 +349,9 @@ void ChromePluginPlaceholder::ShowContextMenu(
     params.custom_items.push_back(separator_item);
   }
 
-  if (!GetPluginInfo().path.value().empty()) {
+  bool flash_hidden =
+      status_ == ChromeViewHostMsg_GetPluginInfo_Status::kFlashHiddenPreferHtml;
+  if (!GetPluginInfo().path.value().empty() && !flash_hidden) {
     content::MenuItem run_item;
     run_item.action = chrome::MENU_COMMAND_PLUGIN_RUN;
     // Disable this menu item if the plugin is blocked by policy.
@@ -354,6 +360,15 @@ void ChromePluginPlaceholder::ShowContextMenu(
     params.custom_items.push_back(run_item);
   }
 
+  if (flash_hidden) {
+    content::MenuItem enable_flash_item;
+    enable_flash_item.action = chrome::MENU_COMMAND_ENABLE_FLASH;
+    enable_flash_item.enabled = true;
+    enable_flash_item.label =
+        l10n_util::GetStringUTF16(IDS_CONTENT_CONTEXT_ENABLE_FLASH);
+    params.custom_items.push_back(enable_flash_item);
+  }
+
   content::MenuItem hide_item;
   hide_item.action = chrome::MENU_COMMAND_PLUGIN_HIDE;
   bool is_main_frame_plugin_document =