media: Bundle Widevine CDM on Win/Mac.

chrome/browser/component_updater/widevine_cdm_component_installer.cc

Index: chrome/browser/component_updater/widevine_cdm_component_installer.cc
diff --git a/chrome/browser/component_updater/widevine_cdm_component_installer.cc b/chrome/browser/component_updater/widevine_cdm_component_installer.cc
index 4279e0b95beab98918ad408a53e01a91accea26a..f0429a0cb3ee6168ede0f97ddccf3e2ddcd2ad3f 100644
--- a/chrome/browser/component_updater/widevine_cdm_component_installer.cc
+++ b/chrome/browser/component_updater/widevine_cdm_component_installer.cc
@@ -347,12 +347,17 @@ void WidevineCdmComponentInstallerTraits::UpdateCdmAdapter(
           << " adapter_install_path=" << adapter_install_path.AsUTF8Unsafe()
           << " adapter_version_path=" << adapter_version_path.AsUTF8Unsafe();
 
+  base::FilePath adapter_source_path;
+  PathService::Get(chrome::FILE_WIDEVINE_CDM_ADAPTER, &adapter_source_path);
+
   const std::string chrome_version = version_info::GetVersionNumber();
   DCHECK(!chrome_version.empty());
   std::string adapter_version;
-  if (!base::ReadFileToString(adapter_version_path, &adapter_version) ||
-      adapter_version != chrome_version ||
-      !base::PathExists(adapter_install_path)) {
+
+  if (adapter_install_path != adapter_source_path &&

[xhwang, 2016/05/20 19:30:00]

Being paranoid about this check... If there's an issue in this code (I don't
know how), we could end up overwritting the bundled adapter on line 369. Maybe
we should check that if the install path is within DIR_COMPONENT, don't copy,
just to be on the safer side?

[ddorwin, 2016/05/20 21:37:22]

You should have a comment to explain this. To isolate the condition, break it
up:

if (!=) 
  NOTREACHED() << Reason;
  return;
}

[xhwang, 2016/05/20 23:46:11]

Updated comments.

+      (!base::ReadFileToString(adapter_version_path, &adapter_version) ||
+       adapter_version != chrome_version ||
+       !base::PathExists(adapter_install_path))) {
     int bytes_written = base::WriteFile(
         adapter_version_path, chrome_version.data(), chrome_version.size());
     if (bytes_written < 0 ||
@@ -361,8 +366,6 @@ void WidevineCdmComponentInstallerTraits::UpdateCdmAdapter(
       // Ignore version file writing failure and try to copy the CDM adapter.
     }
 
-    base::FilePath adapter_source_path;
-    PathService::Get(chrome::FILE_WIDEVINE_CDM_ADAPTER, &adapter_source_path);
     if (!base::CopyFile(adapter_source_path, adapter_install_path)) {
       PLOG(WARNING) << "Failed to copy Widevine CDM adapter.";
       return;