Revert of Moved logic for mapping child process FDs for ICU and V8 into child_process_launcher.cc

ash/shell/content_client/shell_content_browser_client.cc

Index: ash/shell/content_client/shell_content_browser_client.cc
diff --git a/ash/shell/content_client/shell_content_browser_client.cc b/ash/shell/content_client/shell_content_browser_client.cc
index d75e759a5ebcf170080c0e1d559431be76440457..5f2adc52760962cd394b47f1db8b65686874c8ef 100644
--- a/ash/shell/content_client/shell_content_browser_client.cc
+++ b/ash/shell/content_client/shell_content_browser_client.cc
@@ -6,14 +6,22 @@
 
 #include "ash/shell/content_client/shell_browser_main_parts.h"
 #include "base/command_line.h"
+#include "content/public/common/content_descriptors.h"
+#include "content/public/common/content_switches.h"
 #include "content/shell/browser/shell_browser_context.h"
+#include "gin/v8_initializer.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 
 namespace ash {
 namespace shell {
 
 ShellContentBrowserClient::ShellContentBrowserClient()
-    : shell_browser_main_parts_(nullptr) {
+    :
+#if defined(OS_POSIX) && !defined(OS_MACOSX)
+      v8_natives_fd_(-1),
+      v8_snapshot_fd_(-1),
+#endif  // OS_POSIX && !OS_MACOSX
+      shell_browser_main_parts_(nullptr) {
 }
 
 ShellContentBrowserClient::~ShellContentBrowserClient() {
@@ -35,6 +43,46 @@
                                              request_interceptors.Pass());
 }
 
+void ShellContentBrowserClient::AppendMappedFileCommandLineSwitches(
+    base::CommandLine* command_line) {
+#if defined(OS_POSIX) && !defined(OS_MACOSX)
+#if defined(V8_USE_EXTERNAL_STARTUP_DATA)
+  std::string process_type =
+      command_line->GetSwitchValueASCII(switches::kProcessType);
+  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
+#endif  // OS_POSIX && !OS_MACOSX
+}
+
+#if defined(OS_POSIX) && !defined(OS_MACOSX)
+void ShellContentBrowserClient::GetAdditionalMappedFilesForChildProcess(
+    const base::CommandLine& command_line,
+    int child_process_id,
+    content::FileDescriptorInfo* mappings) {
+#if defined(V8_USE_EXTERNAL_STARTUP_DATA)
+  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);
+    }
+  }
+  // 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
+}
+#endif  // OS_POSIX && !OS_MACOSX
+
 content::ShellBrowserContext* ShellContentBrowserClient::browser_context() {
   return shell_browser_main_parts_->browser_context();
 }