Use HTTP response headers for PNaCl caching instead of bitcode hash.

ppapi/native_client/src/trusted/plugin/plugin.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.
 
 #ifdef _MSC_VER
 // Do not warn about use of std::copy with raw pointers.
 #pragma warning(disable : 4996)
 #endif
 
 #include "native_client/src/trusted/plugin/plugin.h"
@@ skipping 1167 matching lines @@
         NexeFileDidOpen(PP_OK);
       } else {
         pp::CompletionCallback open_callback =
             callback_factory_.NewCallback(&Plugin::NexeFileDidOpen);
         // Will always call the callback on success or failure.
         CHECK(
             nexe_downloader_.Open(program_url,
                                   DOWNLOAD_TO_FILE,
                                   open_callback,
                                   true,
-                                  &UpdateDownloadProgress));
+                                  &UpdateDownloadProgress,
+                                  true));
       }
       return;
     }
   }
   // Failed to select the program and/or the translator.
   ReportLoadError(error_info);
 }
 
 void Plugin::RequestNaClManifest(const nacl::string& url) {
   PLUGIN_PRINTF(("Plugin::RequestNaClManifest (url='%s')\n", url.c_str()));
@@ skipping 24 matching lines @@
   bool is_data_uri = GetUrlScheme(nmf_resolved_url.AsString()) == SCHEME_DATA;
   HistogramEnumerateManifestIsDataURI(static_cast<int>(is_data_uri));
   if (is_data_uri) {
     pp::CompletionCallback open_callback =
         callback_factory_.NewCallback(&Plugin::NaClManifestBufferReady);
     // Will always call the callback on success or failure.
     CHECK(nexe_downloader_.Open(nmf_resolved_url.AsString(),
                                 DOWNLOAD_TO_BUFFER,
                                 open_callback,
                                 false,
-                                NULL));
+                                NULL,
+                                true));
   } else {
     pp::CompletionCallback open_callback =
         callback_factory_.NewCallback(&Plugin::NaClManifestFileDidOpen);
     // Will always call the callback on success or failure.
     CHECK(nexe_downloader_.Open(nmf_resolved_url.AsString(),
                                 DOWNLOAD_TO_FILE,
                                 open_callback,
                                 false,
-                                NULL));
+                                NULL,
+                                true));
   }
 }
 
 
 bool Plugin::SetManifestObject(const nacl::string& manifest_json,
                                ErrorInfo* error_info) {
   PLUGIN_PRINTF(("Plugin::SetManifestObject(): manifest_json='%s'.\n",
        manifest_json.c_str()));
   if (error_info == NULL)
     return false;
@@ skipping 71 matching lines @@
     return true;
   }
 
   pp::CompletionCallback open_callback = callback_factory_.NewCallback(
       &Plugin::UrlDidOpenForStreamAsFile, downloader, callback);
   // If true, will always call the callback on success or failure.
   return downloader->Open(url,
                           DOWNLOAD_TO_FILE,
                           open_callback,
                           true,
-                          &UpdateDownloadProgress);
+                          &UpdateDownloadProgress,
+                          true);
 }
 
 
 void Plugin::ReportLoadSuccess(LengthComputable length_computable,
                                uint64_t loaded_bytes,
                                uint64_t total_bytes) {
   // Set the readyState attribute to indicate loaded.
   set_nacl_ready_state(DONE);
   // Inform JavaScript that loading was successful and is complete.
   const nacl::string& url = nexe_downloader_.url_to_open();
@@ skipping 292 matching lines @@
                                           static_cast<uint32_t>(text.size()));
   const PPB_Console* console_interface =
       static_cast<const PPB_Console*>(
           module->GetBrowserInterface(PPB_CONSOLE_INTERFACE));
   console_interface->LogWithSource(pp_instance(), PP_LOGLEVEL_LOG, prefix, str);
   var_interface->Release(prefix);
   var_interface->Release(str);
 }
 
 }  // namespace plugin