Always enable the mime-handler-view feature for OOP PDF

chrome/common/chrome_content_client.cc

Index: chrome/common/chrome_content_client.cc
diff --git a/chrome/common/chrome_content_client.cc b/chrome/common/chrome_content_client.cc
index 9e46c3a397ae4409903671bb5bd16f45fdea3b2a..abf48caa776acd9a829d0534334602b4b47bf7fd 100644
--- a/chrome/common/chrome_content_client.cc
+++ b/chrome/common/chrome_content_client.cc
@@ -29,6 +29,7 @@
 #include "content/public/common/url_constants.h"
 #include "content/public/common/user_agent.h"
 #include "extensions/common/constants.h"
+#include "extensions/common/feature_switch.h"
 #include "gpu/config/gpu_info.h"
 #include "net/http/http_util.h"
 #include "ui/base/l10n/l10n_util.h"
@@ -141,6 +142,9 @@ void ComputeBuiltInPlugins(std::vector<content::PepperPluginInfo>* plugins) {
       pdf.name = ChromeContentClient::kPDFPluginName;
       if (CommandLine::ForCurrentProcess()->HasSwitch(
               switches::kOutOfProcessPdf)) {
+        // Always enable the MIME handler view flag for OOP PDF.
+        extensions::FeatureSwitch::mime_handler_view()->SetOverrideValue(
+            extensions::FeatureSwitch::OVERRIDE_ENABLED);
         pdf.is_out_of_process = true;
         content::WebPluginMimeType pdf_mime_type(kPDFPluginOutOfProcessMimeType,
                                                  kPDFPluginExtension,