Set up a NaCl load status callback to start replacing "start_module".

components/nacl/renderer/trusted_plugin_channel.cc

Index: components/nacl/renderer/trusted_plugin_channel.cc
diff --git a/components/nacl/renderer/trusted_plugin_channel.cc b/components/nacl/renderer/trusted_plugin_channel.cc
index 729644cb089458632312aab5d879811dadf723a0..a6581767e127a702b7d3c467b80da9655c641b19 100644
--- a/components/nacl/renderer/trusted_plugin_channel.cc
+++ b/components/nacl/renderer/trusted_plugin_channel.cc
@@ -6,10 +6,12 @@
 
 #include "base/callback_helpers.h"
 #include "components/nacl/common/nacl_renderer_messages.h"
+#include "components/nacl/renderer/histogram.h"
 #include "components/nacl/renderer/nexe_load_manager.h"
 #include "content/public/renderer/render_thread.h"
 #include "ipc/ipc_sync_channel.h"
 #include "ipc/ipc_message_macros.h"
+#include "native_client/src/trusted/service_runtime/nacl_error_code.h"
 #include "ppapi/c/pp_errors.h"
 
 namespace nacl {
@@ -18,9 +20,9 @@ TrustedPluginChannel::TrustedPluginChannel(
     NexeLoadManager* nexe_load_manager,
     const IPC::ChannelHandle& handle,
     base::WaitableEvent* shutdown_event,
-    bool report_exit_status)
+    bool is_helper_nexe)
     : nexe_load_manager_(nexe_load_manager),
-      report_exit_status_(report_exit_status) {
+      is_helper_nexe_(is_helper_nexe) {
   channel_ = IPC::SyncChannel::Create(
       handle,
       IPC::Channel::MODE_CLIENT,
@@ -41,19 +43,41 @@ bool TrustedPluginChannel::OnMessageReceived(const IPC::Message& msg) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(TrustedPluginChannel, msg)
     IPC_MESSAGE_HANDLER(NaClRendererMsg_ReportExitStatus, OnReportExitStatus);
+    IPC_MESSAGE_HANDLER(NaClRendererMsg_ReportLoadStatus, OnReportLoadStatus);
     IPC_MESSAGE_UNHANDLED(handled = false);
   IPC_END_MESSAGE_MAP()
   return handled;
 }
 
 void TrustedPluginChannel::OnChannelError() {
-  if (report_exit_status_)
+  if (!is_helper_nexe_)
     nexe_load_manager_->NexeDidCrash();
 }
 
 void TrustedPluginChannel::OnReportExitStatus(int exit_status) {
-  if (report_exit_status_)
+  if (!is_helper_nexe_)
     nexe_load_manager_->set_exit_status(exit_status);
 }
 
+void TrustedPluginChannel::OnReportLoadStatus(int load_status) {
+  if (load_status < 0 || load_status > NACL_ERROR_CODE_MAX) {
+    load_status = LOAD_STATUS_UNKNOWN;
+  }
+  // For now, we only report UMA for non-helper nexes
+  // (don't report for the PNaCl translators nexes).
+  if (!is_helper_nexe_) {
+    HistogramEnumerate("NaCl.LoadStatus.SelLdr", load_status,
+                       NACL_ERROR_CODE_MAX);
+    const char* name = nexe_load_manager_->is_installed()
+                           ? "NaCl.LoadStatus.SelLdr.InstalledApp"
+                           : "NaCl.LoadStatus.SelLdr.NotInstalledApp";
+    HistogramEnumerate(name, load_status, NACL_ERROR_CODE_MAX);
+  }
+  if (load_status != LOAD_OK) {
+    nexe_load_manager_->ReportLoadError(
+        PP_NACL_ERROR_SEL_LDR_START_STATUS,
+        NaClErrorString(static_cast<NaClErrorCode>(load_status)));
+  }
+}
+
 }  // namespace nacl