Register a fake Flash with chrome://plugins during browser start-up.

chrome/browser/plugins/plugin_info_message_filter.cc

Index: chrome/browser/plugins/plugin_info_message_filter.cc
diff --git a/chrome/browser/plugins/plugin_info_message_filter.cc b/chrome/browser/plugins/plugin_info_message_filter.cc
index bee46bea0234e0b155ac69059978fa6e2e2a16af..691bb87cf5fa358c37a5873ed913600ebbb5b21b 100644
--- a/chrome/browser/plugins/plugin_info_message_filter.cc
+++ b/chrome/browser/plugins/plugin_info_message_filter.cc
@@ -24,6 +24,7 @@
 #include "chrome/browser/plugins/plugin_prefs.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser_otr_state.h"
+#include "chrome/common/chrome_content_client.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/common/render_messages.h"
 #include "components/component_updater/component_updater_service.h"
@@ -404,6 +405,13 @@ bool PluginInfoMessageFilter::Context::FindEnabledPlugin(
   std::vector<std::string> mime_types;
   PluginService::GetInstance()->GetPluginInfoArray(
       url, mime_type, allow_wildcard, &matching_plugins, &mime_types);
+  base::FilePath notPresent =
+      base::FilePath::FromUTF8Unsafe(ChromeContentClient::kNotPresent);

[Will Harris, 2016/08/26 22:52:35]

kNotPresent definition is only available for GOOGLE_CHROME_BUILD

[waffles, 2016/08/26 23:10:04]

Whoops! Done... although maybe it's better to just define it for Chromium as
well? Let me know.

+  matching_plugins.erase(
+      std::remove_if(
+          matching_plugins.begin(), matching_plugins.end(),
+          [&](const WebPluginInfo& info) { return info.path == notPresent; }),
+      matching_plugins.end());
   if (matching_plugins.empty()) {
     *status = ChromeViewHostMsg_GetPluginInfo_Status::kNotFound;
     return false;