Don't apply the SandboxPlugins flag until we know a plugin will be used

third_party/WebKit/Source/core/html/HTMLPlugInElement.h

Index: third_party/WebKit/Source/core/html/HTMLPlugInElement.h
diff --git a/third_party/WebKit/Source/core/html/HTMLPlugInElement.h b/third_party/WebKit/Source/core/html/HTMLPlugInElement.h
index e42c201323ebfc0538eeb349c9fa8f3059a23ef9..bbd628f927e2443d14faf3948f1b2a230a8003b2 100644
--- a/third_party/WebKit/Source/core/html/HTMLPlugInElement.h
+++ b/third_party/WebKit/Source/core/html/HTMLPlugInElement.h
@@ -130,6 +130,7 @@ private:
 
     bool loadPlugin(const KURL&, const String& mimeType, const Vector<String>& paramNames, const Vector<String>& paramValues, bool useFallback, bool requireLayoutObject);
     bool pluginIsLoadable(const KURL&, const String& mimeType);

[pdr., 2016/02/02 04:32:42]

Can you add a short comment here that mentions the difference between
pluginIsLoadable and objectIsLoadable? I.e., they check different things and
both need to be checked for plugins.

[fs, 2016/02/22 18:36:56]

I renamed these two a bit in the latest PS, so hopefully the names are more
descriptive - I did add comments too though (belt _and_ suspenders).

+    bool objectIsLoadable(const KURL&, const String& mimeType);
     bool wouldLoadAsNetscapePlugin(const String& url, const String& serviceType);
 
     void setPersistedPluginWidget(Widget*);