Prefer System Flash over non-local component updated Flash.

chrome/browser/component_updater/pepper_flash_component_installer.cc

 // Copyright (c) 2013 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/component_updater/pepper_flash_component_installer.h"
 
 #include <stddef.h>
 
 #include <memory>
 #include <string>
@@ skipping 126 matching lines @@
                                            content::kFlashPluginSplExtension,
                                            content::kFlashPluginName);
   plugin_info->mime_types.push_back(spl_mime_type);
   return true;
 }
 
 bool IsPepperFlash(const content::WebPluginInfo& plugin) {
   // We try to recognize Pepper Flash by the following criteria:
   // * It is a Pepper plugin.
   // * It has the special Flash permissions.
+
   return plugin.is_pepper_plugin() &&
          (plugin.pepper_permissions & ppapi::PERMISSION_FLASH);
 }
 
 void RegisterPepperFlashWithChrome(const base::FilePath& path,
                                    const Version& version) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   content::PepperPluginInfo plugin_info;
   if (!MakePepperFlashPluginInfo(path, version, true, &plugin_info))
     return;
 
+  bool is_on_network = base::IsOnNetworkDrive(path);
+
+  base::FilePath bundled_flash_path;
+  PathService::Get(chrome::DIR_PEPPER_FLASH_PLUGIN, &bundled_flash_path);

[Lei Zhang, 2016/04/15 21:16:36]

This can potentially fail. Do you care to check or can you just work with an
empty |bundled_flash_path| ?

[Will Harris, 2016/04/15 21:43:28]

checking below, although FilePath::IsParent always returns false if the FilePath
is empty.

+
   std::vector<content::WebPluginInfo> plugins;
   PluginService::GetInstance()->GetInternalPlugins(&plugins);
-  for (std::vector<content::WebPluginInfo>::const_iterator it =
-            plugins.begin();
-        it != plugins.end();
-        ++it) {
-    if (!IsPepperFlash(*it))
+  for (auto plugin : plugins) {

[Lei Zhang, 2016/04/15 21:16:36]

const auto & ?

[Will Harris, 2016/04/15 21:43:28]

Done.

+    if (!IsPepperFlash(plugin))
       continue;
 
     // Do it only if the version we're trying to register is newer.
-    Version registered_version(base::UTF16ToUTF8(it->version));
+    bool registered_is_bundled = bundled_flash_path.IsParent(plugin.path);
+    Version registered_version(base::UTF16ToUTF8(plugin.version));
+
+    // If lower version, never register.
     if (registered_version.IsValid() &&
-        version.CompareTo(registered_version) <= 0) {
+        version.CompareTo(registered_version) < 0) {
+      return;
+    }
+
+    // If equal version, register iff component is not on a network drive,
+    // and the version of flash is not bundled.
+    if (registered_version.IsValid() &&
+        version.CompareTo(registered_version) == 0 &&
+        (is_on_network || registered_is_bundled)) {
       return;
     }
 
     // If the version is newer, remove the old one first.
-    PluginService::GetInstance()->UnregisterInternalPlugin(it->path);
+    PluginService::GetInstance()->UnregisterInternalPlugin(plugin.path);
     break;
   }
 
   PluginService::GetInstance()->RegisterInternalPlugin(
       plugin_info.ToWebPluginInfo(), true);
   PluginService::GetInstance()->RefreshPlugins();
 }
 #endif  // !defined(OS_LINUX) || defined(GOOGLE_CHROME_BUILD)
 
 }  // namespace
@@ skipping 193 matching lines @@
   base::CommandLine* cmd_line = base::CommandLine::ForCurrentProcess();
   if (cmd_line->HasSwitch(switches::kDisableBundledPpapiFlash))
     return;
   BrowserThread::PostTask(BrowserThread::FILE,
                           FROM_HERE,
                           base::Bind(&StartPepperFlashUpdateRegistration, cus));
 #endif  // defined(GOOGLE_CHROME_BUILD)
 }
 
 }  // namespace component_updater