<webview>: Change how plugin load works inside guests.

chrome/browser/plugins/plugin_info_message_filter.cc

Index: chrome/browser/plugins/plugin_info_message_filter.cc
diff --git a/chrome/browser/plugins/plugin_info_message_filter.cc b/chrome/browser/plugins/plugin_info_message_filter.cc
index 9a15415a236673d54e8491f1d6d93d6fc9b35be0..1acc624455e3d7927bd3ef0232a5cddd646ffedf 100644
--- a/chrome/browser/plugins/plugin_info_message_filter.cc
+++ b/chrome/browser/plugins/plugin_info_message_filter.cc
@@ -11,6 +11,7 @@
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/content_settings/content_settings_utils.h"
 #include "chrome/browser/content_settings/host_content_settings_map.h"
+#include "chrome/browser/extensions/extension_renderer_state.h"
 #include "chrome/browser/plugins/chrome_plugin_service_filter.h"
 #include "chrome/browser/plugins/plugin_finder.h"
 #include "chrome/browser/plugins/plugin_metadata.h"
@@ -199,6 +200,17 @@ void PluginInfoMessageFilter::Context::DecidePluginStatus(
     return;
   }
 #endif
+  if (plugin.type == WebPluginInfo::PLUGIN_TYPE_NPAPI) {
+    CHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
+    // NPAPI plugins are not supported inside <webview> guests.
+    ExtensionRendererState::WebViewInfo info;
+    if (ExtensionRendererState::GetInstance()->GetWebViewInfo(
+            render_process_id_, params.render_view_id, &info)) {
+      status->value =
+          ChromeViewHostMsg_GetPluginInfo_Status::kNPAPINotSupported;

[Bernhard Bauer, 2013/09/26 06:19:39]

On Windows in Metro mode (see above) this triggers an infobar. Will you get that
here too?

[sadrul, 2013/09/26 06:43:23]

It won't. Infobars are not supported for guests inside <webview>. So in these
cases, the plugin is just not loaded.

It is a deliberate decision to not allow NPAPI plugins inside guests, and so
this doesn't trigger any event in the embedder either.

[Bernhard Bauer, 2013/09/26 06:56:33]

Oh, I see, the PluginPermissionFilter filters the message out, right?

[sadrul, 2013/09/26 06:59:52]

The PluginPermissionHelper doesn't actually handle those messages at the moment.
But the messages aren't handled by anything else either (the WebContents for the
guest does not get a PluginObserver). Would you suggest the
PluginPermissionHelper explicitly adds no-op callback for these messages?

[Bernhard Bauer, 2013/09/26 08:39:09]

Hm, I thought we DCHECK if we can't find a handler for a message. If we don't...
hm, yeah, it's probably nice at least for documentation purposes to know that
the messages are swallowed.

[sadrul, 2013/09/26 15:35:26]

Done.

+      return;
+    }
+  }
 
   ContentSetting plugin_setting = CONTENT_SETTING_DEFAULT;
   bool uses_default_content_setting = true;
@@ -250,6 +262,19 @@ void PluginInfoMessageFilter::Context::DecidePluginStatus(
     status->value = ChromeViewHostMsg_GetPluginInfo_Status::kClickToPlay;
   else if (plugin_setting == CONTENT_SETTING_BLOCK)
     status->value = ChromeViewHostMsg_GetPluginInfo_Status::kBlocked;
+
+  if (status->value == ChromeViewHostMsg_GetPluginInfo_Status::kAllowed) {
+    // Allow an embedder of <webview> to block a plugin from being loaded inside
+    // the guest. In order to do this, set the status to 'Unauthorized' here,
+    // and update the status as appropriate depending on the response from the
+    // embedder.
+    ExtensionRendererState::WebViewInfo info;
+    if (ExtensionRendererState::GetInstance()->GetWebViewInfo(
+            render_process_id_, params.render_view_id, &info)) {
+      status->value =
+          ChromeViewHostMsg_GetPluginInfo_Status::kUnauthorized;
+    }
+  }
 }
 
 bool PluginInfoMessageFilter::Context::FindEnabledPlugin(