Add GetPluginRefererURL to PPB_URLUtil_Dev interface to get the 'Referer' HTTP header value that wa…

content/renderer/pepper/pepper_plugin_instance_impl.cc

Index: content/renderer/pepper/pepper_plugin_instance_impl.cc
===================================================================
--- content/renderer/pepper/pepper_plugin_instance_impl.cc	(revision 219784)
+++ content/renderer/pepper/pepper_plugin_instance_impl.cc	(working copy)
@@ -93,6 +93,7 @@
 #include "third_party/WebKit/public/web/WebBindings.h"
 #include "third_party/WebKit/public/web/WebCompositionUnderline.h"
 #include "third_party/WebKit/public/web/WebCursorInfo.h"
+#include "third_party/WebKit/public/web/WebDataSource.h"
 #include "third_party/WebKit/public/web/WebDocument.h"
 #include "third_party/WebKit/public/web/WebElement.h"
 #include "third_party/WebKit/public/web/WebFrame.h"
@@ -2498,6 +2499,20 @@
                                                       components);
 }
 
+PP_Var PepperPluginInstanceImpl::GetPluginRefererURL(
+    PP_Instance instance,
+    PP_URLComponents_Dev* components) {
+  WebFrame* frame = container_->element().document().frame();
+  if (!frame)
+    return PP_MakeUndefined();
+  const WebURLRequest& request = frame->dataSource()->originalRequest();
+  WebString referer = request.httpHeaderField("Referer");
+  if (referer.isEmpty())
+    return PP_MakeUndefined();
+  return ::ppapi::PPB_URLUtil_Shared::GenerateURLReturn(GURL(referer),
+                                                        components);
+}
+
 PP_ExternalPluginResult PepperPluginInstanceImpl::ResetAsProxied(
     scoped_refptr<PluginModule> module) {
   // Save the original module and switch over to the new one now that this