Add UMA reporting on failure to load ppapi plugins.

content/public/plugin/content_plugin_client.h

Index: content/public/plugin/content_plugin_client.h
diff --git a/content/public/plugin/content_plugin_client.h b/content/public/plugin/content_plugin_client.h
index b89e46a42826b32b4140559bb64654129df3be12..a6f70b063946aeb11299b3aec691af82e8802594 100644
--- a/content/public/plugin/content_plugin_client.h
+++ b/content/public/plugin/content_plugin_client.h
@@ -5,6 +5,7 @@
 #ifndef CONTENT_PUBLIC_PLUGIN_CONTENT_PLUGIN_CLIENT_H_
 #define CONTENT_PUBLIC_PLUGIN_CONTENT_PLUGIN_CLIENT_H_
 
+#include "base/files/file_path.h"
 #include "base/string16.h"
 #include "content/public/common/content_client.h"
 
@@ -13,6 +14,17 @@ namespace content {
 // Embedder API for participating in plugin logic.
 class CONTENT_EXPORT ContentPluginClient {
  public:
+  // Make sure the enum list in tools/histogram/histograms.xml is updated with
+  // any change in this list.
+  enum PluginLoadResult {
+    LOAD_SUCCESS,
+    LOAD_FAILED,
+    ENTRY_POINT_MISSING,
+    INIT_FAILED,
+    // NOTE: Add new values only immediately above this line.
+    LOAD_STATUS_MAX  // Boundary value for UMA_HISTOGRAM_ENUMERATION.
+  };
+
   virtual ~ContentPluginClient() {}
 
   // Called to perform any per-process initialization necessary before
@@ -21,6 +33,11 @@ class CONTENT_EXPORT ContentPluginClient {
 
   // Notifies that a plugin process has started.
   virtual void PluginProcessStarted(const string16& plugin_name) {}
+
+  // Notifies the plugin loading result.
+  virtual void PluginLoaded(const base::FilePath& plugin_path,
+                            bool is_broker,
+                            PluginLoadResult result) {}
 };
 
 }  // namespace content