PDF: Add UMA to track successful / failed PDF loads

chrome/renderer/plugins/plugin_uma.cc

Index: chrome/renderer/plugins/plugin_uma.cc
diff --git a/chrome/renderer/plugins/plugin_uma.cc b/chrome/renderer/plugins/plugin_uma.cc
index 0aceead0d76a1286e9ed80c60c35aafa1e331766..c076c8260804ab6898aa1b3f62ca530b169ced2b 100644
--- a/chrome/renderer/plugins/plugin_uma.cc
+++ b/chrome/renderer/plugins/plugin_uma.cc
@@ -66,6 +66,12 @@ PluginUMAReporter* PluginUMAReporter::GetInstance() {
   return base::Singleton<PluginUMAReporter>::get();
 }
 
+// static
+void PluginUMAReporter::ReportPDFLoadStatus(PDFLoadStatus status) {
+  UMA_HISTOGRAM_ENUMERATION("PDF.LoadStatus", status,
+                            PluginUMAReporter::PDF_LOAD_STATUS_MAX);
+}
+
 void PluginUMAReporter::ReportPluginMissing(const std::string& plugin_mime_type,
                                             const GURL& plugin_src) {
   report_sender_->SendPluginUMA(MISSING_PLUGIN,