Allow startup with missing V8 snapshot file.

chromecast/browser/cast_content_browser_client.cc

 // Copyright 2014 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 "chromecast/browser/cast_content_browser_client.h"
 
 #include <string>
 
 #include "base/base_switches.h"
 #include "base/command_line.h"
@@ skipping 128 matching lines @@
   }
 
   if (scheme == url::kFileScheme) {
     return base::CommandLine::ForCurrentProcess()->HasSwitch(
         switches::kEnableLocalFileAccesses);
   }
 
   return false;
 }
 
+void CastContentBrowserClient::AppendMappedFileCommandLineSwitches(
+    base::CommandLine* command_line) {
+  std::string process_type =
+      command_line->GetSwitchValueNative(switches::kProcessType);
+
+#if defined(V8_USE_EXTERNAL_STARTUP_DATA)
+  if (process_type != switches::kZygoteProcess) {
+    DCHECK(natives_fd_exists());
+    command_line->AppendSwitch(::switches::kV8NativesPassedByFD);
+    if (snapshot_fd_exists())
+      command_line->AppendSwitch(::switches::kV8SnapshotPassedByFD);
+  }
+}
+
+#endif  // V8_USE_EXTERNAL_STARTUP_DATA
 void CastContentBrowserClient::AppendExtraCommandLineSwitches(
     base::CommandLine* command_line,
     int child_process_id) {
-
   std::string process_type =
       command_line->GetSwitchValueNative(switches::kProcessType);
   base::CommandLine* browser_command_line =
       base::CommandLine::ForCurrentProcess();
 
-#if defined(V8_USE_EXTERNAL_STARTUP_DATA)
-  if (process_type != switches::kZygoteProcess) {
-    command_line->AppendSwitch(::switches::kV8NativesPassedByFD);
-    command_line->AppendSwitch(::switches::kV8SnapshotPassedByFD);
-  }
-#endif  // V8_USE_EXTERNAL_STARTUP_DATA
-
   // IsCrashReporterEnabled() is set when InitCrashReporter() is called, and
   // controlled by GetBreakpadClient()->EnableBreakpadForProcess(), therefore
   // it's ok to add switch to every process here.
   if (breakpad::IsCrashReporterEnabled()) {
     command_line->AppendSwitch(switches::kEnableCrashReporter);
   }
 
   // Renderer process command-line
   if (process_type == switches::kRendererProcess) {
     // Any browser command-line switches that should be propagated to
@@ skipping 134 matching lines @@
     bool* no_javascript_access) {
   *no_javascript_access = true;
   return false;
 }
 
 void CastContentBrowserClient::GetAdditionalMappedFilesForChildProcess(
     const base::CommandLine& command_line,
     int child_process_id,
     content::FileDescriptorInfo* mappings) {
 #if defined(V8_USE_EXTERNAL_STARTUP_DATA)
-  if (v8_natives_fd_.get() == -1 || v8_snapshot_fd_.get() == -1) {
+  if (!natives_fd_exists()) {
     int v8_natives_fd = -1;
     int v8_snapshot_fd = -1;
     if (gin::V8Initializer::OpenV8FilesForChildProcesses(&v8_natives_fd,
                                                          &v8_snapshot_fd)) {
       v8_natives_fd_.reset(v8_natives_fd);
       v8_snapshot_fd_.reset(v8_snapshot_fd);
     }
   }
-  DCHECK(v8_natives_fd_.get() != -1 && v8_snapshot_fd_.get() != -1);
+  // V8 can't start up without the source of the natives, but it can
+  // start up (slower) without the snapshot.
+  DCHECK(natives_fd_exists());
   mappings->Share(kV8NativesDataDescriptor, v8_natives_fd_.get());
   mappings->Share(kV8SnapshotDataDescriptor, v8_snapshot_fd_.get());
 #endif  // V8_USE_EXTERNAL_STARTUP_DATA
 #if defined(OS_ANDROID)
   const int flags_open_read = base::File::FLAG_OPEN | base::File::FLAG_READ;
   base::FilePath pak_file_path;
   CHECK(PathService::Get(FILE_CAST_PAK, &pak_file_path));
   base::File pak_file(pak_file_path, flags_open_read);
   if (!pak_file.IsValid()) {
     NOTREACHED() << "Failed to open file when creating renderer process: "
@@ skipping 75 matching lines @@
         process_type, dumps_path, false /* upload */);
   // StartUploaderThread() even though upload is diferred.
   // Breakpad-related memory is freed in the uploader thread.
   crash_handler->StartUploaderThread();
   return crash_handler;
 }
 #endif  // !defined(OS_ANDROID)
 
 }  // namespace shell
 }  // namespace chromecast