Transfer v8 snapshot files as file descriptors to child processes on Posix

content/app/content_main_runner.cc

Index: content/app/content_main_runner.cc
diff --git a/content/app/content_main_runner.cc b/content/app/content_main_runner.cc
index 3163a4562ce16bcbd69fa98416b432460dcfb3f5..90d661b0f24b99784a40ac55e90852faf1319760 100644
--- a/content/app/content_main_runner.cc
+++ b/content/app/content_main_runner.cc
@@ -53,10 +53,6 @@
 #include "gin/public/isolate_holder.h"
 #endif
 
-#if defined(OS_ANDROID)
-#include "content/public/common/content_descriptors.h"
-#endif
-
 #if defined(USE_TCMALLOC)
 #include "third_party/tcmalloc/chromium/src/gperftools/malloc_extension.h"
 #if defined(TYPE_PROFILING)
@@ -98,6 +94,7 @@
 #include "content/public/common/content_descriptors.h"
 
 #if !defined(OS_MACOSX)
+#include "content/public/common/content_descriptors.h"
 #include "content/public/common/zygote_fork_delegate_linux.h"
 #endif
 #if !defined(OS_MACOSX) && !defined(OS_ANDROID)
@@ -519,7 +516,16 @@ class ContentMainRunnerImpl : public ContentMainRunner {
 #if defined(OS_LINUX) || defined(OS_OPENBSD)
     g_fds->Set(kCrashDumpSignal,
                kCrashDumpSignal + base::GlobalDescriptors::kBaseDescriptor);
-#endif
+#if defined(V8_USE_EXTERNAL_STARTUP_DATA)
+    g_fds->Set(
+        kV8NativesDataDescriptor,
+        kV8NativesDataDescriptor + base::GlobalDescriptors::kBaseDescriptor);
+    g_fds->Set(
+        kV8SnapshotDataDescriptor,
+        kV8SnapshotDataDescriptor + base::GlobalDescriptors::kBaseDescriptor);
+#endif  // V8_USE_EXTERNAL_STARTUP_DATA
+#endif  // OS_LINUX || OS_OPENBSD
+
 
 #endif  // !OS_WIN
 
@@ -689,33 +695,29 @@ class ContentMainRunnerImpl : public ContentMainRunner {
     } else {
       CHECK(base::i18n::InitializeICU());
     }
+#else
+    CHECK(base::i18n::InitializeICU());
+#endif  // OS_ANDROID
 
 #if defined(V8_USE_EXTERNAL_STARTUP_DATA)
-    int v8_natives_fd = base::GlobalDescriptors::GetInstance()->MaybeGet(
-        kV8NativesDataDescriptor);
-    int v8_snapshot_fd = base::GlobalDescriptors::GetInstance()->MaybeGet(
-        kV8SnapshotDataDescriptor);
-    if (v8_natives_fd != -1 && v8_snapshot_fd != -1) {
-      auto v8_natives_region =
-          base::GlobalDescriptors::GetInstance()->GetRegion(
-              kV8NativesDataDescriptor);
-      auto v8_snapshot_region =
-          base::GlobalDescriptors::GetInstance()->GetRegion(
-              kV8SnapshotDataDescriptor);
+#if defined(OS_POSIX) && !defined(OS_MACOSX)
+    if (process_type.empty() || process_type == switches::kZygoteProcess) {
+      // Load snapshot from file for browser or zygote process.
+      CHECK(gin::IsolateHolder::LoadV8Snapshot());
+    } else {
+      base::GlobalDescriptors* g_fds = base::GlobalDescriptors::GetInstance();
+      int v8_natives_fd = g_fds->Get(kV8NativesDataDescriptor);
+      int v8_snapshot_fd = g_fds->Get(kV8SnapshotDataDescriptor);
+      auto v8_natives_region = g_fds->GetRegion(kV8NativesDataDescriptor);
+      auto v8_snapshot_region = g_fds->GetRegion(kV8SnapshotDataDescriptor);
       CHECK(gin::IsolateHolder::LoadV8SnapshotFd(
           v8_natives_fd, v8_natives_region.offset, v8_natives_region.size,
           v8_snapshot_fd, v8_snapshot_region.offset, v8_snapshot_region.size));
-    } else {
-      CHECK(gin::IsolateHolder::LoadV8Snapshot());
     }
-#endif // V8_USE_EXTERNAL_STARTUP_DATA
-
 #else
-    CHECK(base::i18n::InitializeICU());
-#if defined(V8_USE_EXTERNAL_STARTUP_DATA)
     CHECK(gin::IsolateHolder::LoadV8Snapshot());
+#endif  // OS_POSIX
 #endif  // V8_USE_EXTERNAL_STARTUP_DATA
-#endif  // OS_ANDROID
 
     if (delegate_)
       delegate_->PreSandboxStartup();