Add GetLiveVars to PPB_Testing_Dev. Fix leaks it uncovered.

ppapi/native_client/src/shared/ppapi_proxy/proxy_var_cache.h

Index: ppapi/native_client/src/shared/ppapi_proxy/proxy_var_cache.h
diff --git a/ppapi/native_client/src/shared/ppapi_proxy/proxy_var_cache.h b/ppapi/native_client/src/shared/ppapi_proxy/proxy_var_cache.h
index 41c8d0c522393899125c72100b4145229b19537a..6cec6d457a8ed0bbce819749cc066f6487155438 100644
--- a/ppapi/native_client/src/shared/ppapi_proxy/proxy_var_cache.h
+++ b/ppapi/native_client/src/shared/ppapi_proxy/proxy_var_cache.h
@@ -6,6 +6,7 @@
 #define NATIVE_CLIENT_SRC_SHARED_PPAPI_PROXY_PROXY_VAR_CACHE_H_
 
 #include <map>
+#include <vector>
 
 #include "native_client/src/include/nacl_memory.h"
 #include "native_client/src/shared/ppapi_proxy/proxy_var.h"
@@ -48,6 +49,9 @@ class ProxyVarCache {
   // Find the object in the cache associated with |pp_var|.
   SharedProxyVar SharedProxyVarForVar(PP_Var pp_var) const;
 
+  // Return all live Vars in the tracker. Reference counts are incremented.
+  std::vector<PP_Var> GetLiveVars();
+
  private:
   // Return whether or not a var type is cached.
   // Note to implementers: be sure to add to this function when adding new