Fix PluginImageData and mouselock NaCl example:

ppapi/native_client/src/shared/ppapi_proxy/plugin_ppb_image_data.cc

Index: ppapi/native_client/src/shared/ppapi_proxy/plugin_ppb_image_data.cc
diff --git a/ppapi/native_client/src/shared/ppapi_proxy/plugin_ppb_image_data.cc b/ppapi/native_client/src/shared/ppapi_proxy/plugin_ppb_image_data.cc
index 636b8ed151a294e6bf3ff3a0b57b89ca5b4ae90c..9c2a27acff000f644d5069503d2308d7f5414947 100644
--- a/ppapi/native_client/src/shared/ppapi_proxy/plugin_ppb_image_data.cc
+++ b/ppapi/native_client/src/shared/ppapi_proxy/plugin_ppb_image_data.cc
@@ -140,6 +140,10 @@ PluginImageData::PluginImageData()
       addr_(NULL) {
 }
 
+PluginImageData::~PluginImageData() {
+  Unmap();
+}
+
 bool PluginImageData::InitFromBrowserResource(PP_Resource resource) {
   nacl_abi_size_t desc_size = static_cast<nacl_abi_size_t>(sizeof(desc_));
   int32_t success = PP_FALSE;