Enable win32k lockdown for ppapi processes.

content/public/browser/content_browser_client.cc

Index: content/public/browser/content_browser_client.cc
diff --git a/content/public/browser/content_browser_client.cc b/content/public/browser/content_browser_client.cc
index 47c8cbf9a0a92fa90e80978d199bf3927d00818a..c6a2bec8ef8025b9e882e729dd5366b623e9f8a7 100644
--- a/content/public/browser/content_browser_client.cc
+++ b/content/public/browser/content_browser_client.cc
@@ -417,13 +417,6 @@ base::string16 ContentBrowserClient::GetAppContainerSidForSandboxType(
       L"S-1-15-2-3251537155-1984446955-2931258699-841473695-1938553385-"
       L"924012148-129201922");
 }
-
-bool ContentBrowserClient::IsWin32kLockdownEnabledForMimeType(
-    const std::string& mime_type) const {
-  // TODO(wfh): Enable this by default once Win32k lockdown for PPAPI processes
-  // is enabled by default in Chrome. See crbug.com/523278.
-  return false;
-}
 #endif  // defined(OS_WIN)
 
 std::unique_ptr<base::Value> ContentBrowserClient::GetServiceManifestOverlay(