Prefer System Flash over non-local component updated Flash.

chrome/common/chrome_content_client.cc

 // Copyright (c) 2012 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/common/chrome_content_client.h"
 
 #include <stdint.h>
 
 #include <memory>
 
 #include "base/command_line.h"
 #include "base/debug/crash_logging.h"
 #include "base/files/file_util.h"
 #include "base/json/json_reader.h"
 #include "base/memory/scoped_vector.h"
 #include "base/path_service.h"
 #include "base/strings/string16.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
+#include "base/tuple.h"
 #include "build/build_config.h"
 #include "chrome/common/child_process_logging.h"
 #include "chrome/common/chrome_constants.h"
 #include "chrome/common/chrome_paths.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/crash_keys.h"
 #include "chrome/common/pepper_flash.h"
 #include "chrome/common/secure_origin_whitelist.h"
 #include "chrome/common/url_constants.h"
 #include "chrome/grit/common_resources.h"
@@ skipping 158 matching lines @@
       widevine_cdm.permissions = kWidevineCdmPluginPermissions;
       plugins->push_back(widevine_cdm);
 
       skip_widevine_cdm_file_check = true;
     }
   }
 #endif  // defined(WIDEVINE_CDM_AVAILABLE) && defined(ENABLE_PEPPER_CDMS) &&
         // !defined(WIDEVINE_CDM_IS_COMPONENT)
 }
 
+// Creates a PepperPluginInfo for the specified plugin.
+// |path| is the full path to the plugin.
+// |version| is a string representation of the plugin version.
+// |is_debug| is whether the plugin is the debug version or not.
+// |is_external| is whether the plugin is supplied external to Chrome e.g. a
+//     system installation of Adobe Flash.
+// |is_bundled| distinguishes between component updated plugin and a bundled
+//     plugin.
 content::PepperPluginInfo CreatePepperFlashInfo(const base::FilePath& path,
                                                 const std::string& version,
-                                                bool is_debug) {
+                                                bool is_debug,
+                                                bool is_external,
+                                                bool is_bundled) {
   content::PepperPluginInfo plugin;
 
   plugin.is_out_of_process = true;
   plugin.name = content::kFlashPluginName;
   plugin.path = path;
+#if defined(OS_WIN)
+  plugin.is_on_local_drive = !base::IsOnNetworkDrive(path);
+#endif
   plugin.permissions = chrome::kPepperFlashPermissions;
   plugin.is_debug = is_debug;
+  plugin.is_external = is_external;
+  plugin.is_bundled = is_bundled;
 
   std::vector<std::string> flash_version_numbers = base::SplitString(
       version, ".", base::TRIM_WHITESPACE, base::SPLIT_WANT_NONEMPTY);
   if (flash_version_numbers.size() < 1)
     flash_version_numbers.push_back("11");
   if (flash_version_numbers.size() < 2)
     flash_version_numbers.push_back("2");
   if (flash_version_numbers.size() < 3)
     flash_version_numbers.push_back("999");
   if (flash_version_numbers.size() < 4)
@@ skipping 22 matching lines @@
   if (flash_path.empty())
     return;
 
   // Also get the version from the command-line. Should be something like 11.2
   // or 11.2.123.45.
   std::string flash_version =
       base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
           switches::kPpapiFlashVersion);
 
   plugins->push_back(
-      CreatePepperFlashInfo(base::FilePath(flash_path), flash_version, false));
+      CreatePepperFlashInfo(base::FilePath(flash_path),
+                            flash_version, false, true, false));
 }
 
 #if defined(OS_LINUX)
 // This function tests if DIR_USER_DATA can be accessed, as a simple check to
 // see if the zygote has been sandboxed at this point.
 bool IsUserDataDirAvailable() {
   base::FilePath user_data_dir;
   return PathService::Get(chrome::DIR_USER_DATA, &user_data_dir);
 }
 
@@ skipping 13 matching lines @@
                                                                 &version)) {
       // Test if the file can be mapped as executable. If the user's home
       // directory is mounted noexec, the component flash plugin will not load.
       // By testing for this, Chrome can fallback to the bundled flash plugin.
       if (!component_flash_hint_file::TestExecutableMapping(flash_path)) {
         LOG(WARNING) << "The component updated flash plugin could not be "
                         "mapped as executable. Attempting to fallback to the "
                         "bundled or system plugin.";
         return false;
       }
-      *plugin = CreatePepperFlashInfo(flash_path, version, false);
+      *plugin = CreatePepperFlashInfo(flash_path, version, false, false, false);
       return true;
     }
     LOG(ERROR)
         << "Failed to locate and load the component updated flash plugin.";
   }
 #endif  // defined(FLAPPER_AVAILABLE)
   return false;
 }
 #endif  // defined(OS_LINUX)
 
 bool GetBundledPepperFlash(content::PepperPluginInfo* plugin) {
 #if defined(FLAPPER_AVAILABLE)
   base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
 
   // Ignore bundled Pepper Flash if there is Pepper Flash specified from the
   // command-line.
   if (command_line->HasSwitch(switches::kPpapiFlashPath))
     return false;
 
   bool force_disable =
       command_line->HasSwitch(switches::kDisableBundledPpapiFlash);
   if (force_disable)
     return false;
 
   base::FilePath flash_path;
   if (!PathService::Get(chrome::FILE_PEPPER_FLASH_PLUGIN, &flash_path))
     return false;
 
-  *plugin = CreatePepperFlashInfo(flash_path, FLAPPER_VERSION_STRING, false);
+  *plugin = CreatePepperFlashInfo(flash_path, FLAPPER_VERSION_STRING, false,
+                                  false, true);
   return true;
 #else
   return false;
 #endif  // FLAPPER_AVAILABLE
 }
 
 bool IsSystemFlashScriptDebuggerPresent() {
 #if defined(OS_WIN)
   const wchar_t kFlashRegistryRoot[] =
       L"SOFTWARE\\Macromedia\\FlashPlayerPepper";
   const wchar_t kIsDebuggerValueName[] = L"isScriptDebugger";
 
   base::win::RegKey path_key(HKEY_LOCAL_MACHINE, kFlashRegistryRoot, KEY_READ);
   DWORD debug_value;
   if (path_key.ReadValueDW(kIsDebuggerValueName, &debug_value) != ERROR_SUCCESS)
     return false;
 
   return (debug_value == 1);
 #else
   // TODO(wfh): implement this on OS X and Linux. crbug.com/497996.
   return false;
 #endif
 }
 
 bool GetSystemPepperFlash(content::PepperPluginInfo* plugin) {
   base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
-  bool system_flash_is_debug = IsSystemFlashScriptDebuggerPresent();
-
-#if defined(FLAPPER_AVAILABLE)
-  // If flapper is available, only try the system plugin if either:
-  // --disable-bundled-ppapi-flash is specified, or the system debugger is the
-  // Flash Script Debugger.
-  if (!(command_line->HasSwitch(switches::kDisableBundledPpapiFlash) ||
-        system_flash_is_debug)) {
-    return false;
-  }
-#endif  // defined(FLAPPER_AVAILABLE)
-
   // Do not try and find System Pepper Flash if there is a specific path on
   // the commmand-line.
   if (command_line->HasSwitch(switches::kPpapiFlashPath))
     return false;
 
   base::FilePath flash_filename;
   if (!PathService::Get(chrome::FILE_PEPPER_FLASH_SYSTEM_PLUGIN,
                         &flash_filename))
     return false;
 
@@ skipping 11 matching lines @@
   if (!manifest_value.get())
     return false;
   base::DictionaryValue* manifest = NULL;
   if (!manifest_value->GetAsDictionary(&manifest))
     return false;
 
   Version version;
   if (!chrome::CheckPepperFlashManifest(*manifest, &version))
     return false;
 
-  *plugin = CreatePepperFlashInfo(flash_filename, version.GetString(),
-                                  system_flash_is_debug);
+  *plugin = CreatePepperFlashInfo(flash_filename,
+                                  version.GetString(),
+                                  IsSystemFlashScriptDebuggerPresent(),
+                                  true,
+                                  false);
   return true;
 }
 #endif  //  defined(ENABLE_PLUGINS)
 
 std::string GetProduct() {
   return version_info::GetProductNameAndVersionForUserAgent();
 }
 
 }  // namespace
 
@@ skipping 59 matching lines @@
 #elif defined(OS_POSIX)
   base::debug::SetCrashKeyValue(crash_keys::kGPUVendor, gpu_info.gl_vendor);
   base::debug::SetCrashKeyValue(crash_keys::kGPURenderer, gpu_info.gl_renderer);
 #endif
 }
 
 #if defined(ENABLE_PLUGINS)
 // static
 content::PepperPluginInfo* ChromeContentClient::FindMostRecentPlugin(
     const std::vector<content::PepperPluginInfo*>& plugins) {
-  auto it = std::max_element(
-      plugins.begin(), plugins.end(),
-      [](content::PepperPluginInfo* x, content::PepperPluginInfo* y) {
-        Version version_x(x->version);
-        Version version_y(y->version);
-        DCHECK(version_x.IsValid() && version_y.IsValid());
-        if (version_x == version_y)
-          return !x->is_debug && y->is_debug;
-        return version_x < version_y;
-      });
-  return it != plugins.end() ? *it : nullptr;
+  if (plugins.empty())
+    return nullptr;
+
+  using PluginSortKey = base::Tuple<base::Version, bool, bool, bool, bool>;
+
+  std::map<PluginSortKey, content::PepperPluginInfo*> plugin_map;
+
+  for (const auto& plugin : plugins)
+    plugin_map[PluginSortKey(Version(plugin->version), plugin->is_debug,
+                             plugin->is_bundled, plugin->is_on_local_drive,
+                             !plugin->is_external)] = plugin;
+
+  return plugin_map.rbegin()->second;

[cpu_(ooo_6.6-7.5), 2016/04/20 19:23:14]

mmm... clever but obscure, I don't know what the less() operator is implemented
for tuples.. hopefully it does the right thing.

At least lets keep the DCHECK. also shouldn't be using std::tuple?

[Will Harris, 2016/04/20 23:50:21]

yup less is implemented by "Compares lhs and rhs lexicographically, that is,
compares the first elements, if they are equivalent, compares the second
elements, if those are equivalent, compares the third elements, and so on." so
this code should work. I was doubtful enough about it that I wrote a lot of
tests.

I added the DCHECK back again.

Also, when this CL was made I don't think std:tuple was allowed, but now it is,
so I changed it.

 }
 #endif  // defined(ENABLE_PLUGINS)
 
 void ChromeContentClient::AddPepperPlugins(
     std::vector<content::PepperPluginInfo>* plugins) {
 #if defined(ENABLE_PLUGINS)
   ComputeBuiltInPlugins(plugins);
   AddPepperFlashFromCommandLine(plugins);
 
 #if defined(OS_LINUX)
@@ skipping 152 matching lines @@
 #if defined(ENABLE_EXTENSIONS)
   return extensions::IsIsolateExtensionsEnabled();
 #else
   return false;
 #endif
 }
 
 base::StringPiece ChromeContentClient::GetOriginTrialPublicKey() {
   return origin_trial_key_manager_.GetPublicKey();
 }