Make the PNaCl is not-yet-installed error messages easier to read.

ppapi/native_client/src/trusted/plugin/pnacl_coordinator.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "native_client/src/trusted/plugin/pnacl_coordinator.h"
 
 #include <utility>
 #include <vector>
 
 #include "native_client/src/include/checked_cast.h"
@@ skipping 284 matching lines @@
   // running from the main thread, and by the time it exits, callback_factory_
   // will have been destroyed.  This will result in the cancellation of
   // translation_complete_callback_, so no notification will be delivered.
   if (translate_thread_.get() != NULL) {
     translate_thread_->AbortSubprocesses();
   }
 }
 
 void PnaclCoordinator::ReportNonPpapiError(enum PluginErrorCode err_code,
                                            const nacl::string& message) {
-  error_info_.SetReport(err_code,
-                        nacl::string("PnaclCoordinator: ") + message);
+  error_info_.SetReport(err_code, message);
   ExitWithError();
 }
 
 void PnaclCoordinator::ReportPpapiError(enum PluginErrorCode err_code,
                                         int32_t pp_error,
                                         const nacl::string& message) {
   nacl::stringstream ss;
   ss << "PnaclCoordinator: " << message << " (pp_error=" << pp_error << ").";
   error_info_.SetReport(err_code, ss.str());
   ExitWithError();
@@ skipping 455 matching lines @@
   // Now open the pexe stream.
   streaming_downloader_.reset(new FileDownloader());
   streaming_downloader_->Initialize(plugin_);
 
   // Even though we haven't started downloading, create the translation
   // thread object immediately. This ensures that any pieces of the file
   // that get downloaded before the compilation thread is accepting
   // SRPCs won't get dropped.
   translate_thread_.reset(new PnaclTranslateThread());
   if (translate_thread_ == NULL) {
-    ReportNonPpapiError(ERROR_PNACL_THREAD_CREATE,
-                        "could not allocate translation thread.");
+    ReportNonPpapiError(
+        ERROR_PNACL_THREAD_CREATE,
+        "PnaclCoordinator: could not allocate translation thread.");
     return;
   }
   if (!use_new_cache_) {
     // We also want to open the object file now so the
     // translator can start writing to it during streaming translation.
     obj_file_.reset(new TempFile(plugin_));
     pp::CompletionCallback obj_cb =
         callback_factory_.NewCallback(&PnaclCoordinator::ObjectFileDidOpen);
     obj_file_->Open(obj_cb, true);
   }
 
   pp::CompletionCallback cb =
       callback_factory_.NewCallback(&PnaclCoordinator::BitcodeStreamDidOpen);
   if (!streaming_downloader_->OpenStream(pexe_url_, cb, this)) {
-    ReportNonPpapiError(ERROR_PNACL_PEXE_FETCH_OTHER,
-                        nacl::string("failed to open stream ") + pexe_url_);
+    ReportNonPpapiError(
+        ERROR_PNACL_PEXE_FETCH_OTHER,
+        nacl::string("PnaclCoordinator: failed to open stream ") + pexe_url_);
+    return;
   }
 }
 
 void PnaclCoordinator::BitcodeStreamDidOpen(int32_t pp_error) {
   if (pp_error != PP_OK) {
     BitcodeStreamDidFinish(pp_error);
     return;
   }
 
   if (!off_the_record_) {
@@ skipping 53 matching lines @@
                  nexe_handle_));
   if (pp_error < PP_OK) {
     ReportPpapiError(ERROR_PNACL_CREATE_TEMP, pp_error,
                      nacl::string("GetNexeFd failed"));
     return;
   }
   temp_nexe_file_.reset(new TempFile(plugin_));
   if (!temp_nexe_file_->SetExistingFd(nexe_handle_)) {
     ReportNonPpapiError(
         ERROR_PNACL_CREATE_TEMP,
-        nacl::string("Got bad temp file handle from GetNexeFd"));
+        nacl::string(
+            "PnaclCoordinator: Got bad temp file handle from GetNexeFd"));
     return;
   }
   if (is_cache_hit_ == PP_TRUE) {
     // Cache hit -- no need to stream the rest of the file.
     streaming_downloader_.reset(NULL);
     // TODO(dschuff): update UMA stats for hit/miss once there could actually
     // be hits/misses.
     // Open it for reading as the cached nexe file.
     pp::CompletionCallback cb =
         callback_factory_.NewCallback(&PnaclCoordinator::NexeReadDidOpen);
@@ skipping 156 matching lines @@
                                   obj_file_.get(),
                                   temp_nexe_file_.get(),
                                   &error_info_,
                                   resources_.get(),
                                   &pnacl_options_,
                                   this,
                                   plugin_);
 }
 
 }  // namespace plugin