[HBD] Only use Flash Download interception for DETECT content setting.

chrome/browser/plugins/flash_download_interception.cc

 // Copyright 2016 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 "chrome/browser/plugins/flash_download_interception.h"
 
 #include "base/bind.h"
 #include "base/memory/ptr_util.h"
 #include "base/strings/string_util.h"
+#include "chrome/browser/content_settings/host_content_settings_map_factory.h"
+#include "chrome/browser/plugins/plugins_field_trial.h"
+#include "chrome/browser/profiles/profile.h"
 #include "chrome/common/chrome_features.h"
+#include "components/content_settings/core/browser/host_content_settings_map.h"
 #include "components/navigation_interception/intercept_navigation_throttle.h"
 #include "components/navigation_interception/navigation_params.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/navigation_handle.h"
 #include "content/public/browser/web_contents.h"
 
 using content::BrowserThread;
 using content::NavigationHandle;
 using content::NavigationThrottle;
 
@@ skipping 20 matching lines @@
     return nullptr;
 
   if (!handle->HasUserGesture())
     return nullptr;
 
   if (!base::StartsWith(handle->GetURL().GetContent(), kFlashDownloadURL,
                         base::CompareCase::INSENSITIVE_ASCII)) {
     return nullptr;
   }
 
+  Profile* profile = Profile::FromBrowserContext(
+      handle->GetWebContents()->GetBrowserContext());
+  HostContentSettingsMap* host_content_settings_map =
+      HostContentSettingsMapFactory::GetForProfile(profile);
+  GURL page_url = handle->GetWebContents()->GetLastCommittedURL();
+
+  std::unique_ptr<base::Value> general_setting =
+      host_content_settings_map->GetWebsiteSetting(
+          page_url, page_url, CONTENT_SETTINGS_TYPE_PLUGINS, std::string(),
+          nullptr);
+  ContentSetting plugin_setting =
+      content_settings::ValueToContentSetting(general_setting.get());
+  plugin_setting = PluginsFieldTrial::EffectiveContentSetting(
+      CONTENT_SETTINGS_TYPE_PLUGINS, plugin_setting);
+
+  if (plugin_setting != CONTENT_SETTING_DETECT_IMPORTANT_CONTENT)
+    return nullptr;
+
   return base::MakeUnique<navigation_interception::InterceptNavigationThrottle>(
       handle, base::Bind(&ShouldInterceptNavigation), true);
 }