Load v8 snapshots directly from APK (and store them uncompressed)

ash/shell/content_client/shell_content_browser_client.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 "ash/shell/content_client/shell_content_browser_client.h"
 
 #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()
-    :
-#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) {
+    : shell_browser_main_parts_(nullptr) {
 }
 
 ShellContentBrowserClient::~ShellContentBrowserClient() {
 }
 
 content::BrowserMainParts* ShellContentBrowserClient::CreateBrowserMainParts(
     const content::MainFunctionParams& parameters) {
   shell_browser_main_parts_ =  new ShellBrowserMainParts(parameters);
   return shell_browser_main_parts_;
 }
 
 net::URLRequestContextGetter* ShellContentBrowserClient::CreateRequestContext(
     content::BrowserContext* content_browser_context,
     content::ProtocolHandlerMap* protocol_handlers,
     content::URLRequestInterceptorScopedVector request_interceptors) {
   content::ShellBrowserContext* shell_context =
       static_cast<content::ShellBrowserContext*>(content_browser_context);
   return shell_context->CreateRequestContext(protocol_handlers,
                                              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());
+    DCHECK(v8_files_.natives_fd.is_valid());
     command_line->AppendSwitch(::switches::kV8NativesPassedByFD);
-    if (snapshot_fd_exists())
+    if (v8_files_.snapshot_fd.is_valid()) {
       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(OS_ANDROID)
     , std::map<int, base::MemoryMappedFile::Region>* regions
 #endif
     ) {
 #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);
-    }
+  if (!v8_files_.natives_fd.is_valid()) {
+    gin::V8Initializer::OpenV8FilesForChildProcesses(&v8_files_);
   }
-  // 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());
+  DCHECK(v8_files_.natives_fd.is_valid());
+  mappings->Share(kV8NativesDataDescriptor, v8_files_.natives_fd.get());
+#if defined(OS_ANDROID)
+  regions->insert(
+      std::make_pair(kV8NativesDataDescriptor, v8_files_.natives_region));
+#endif
+  if (v8_files_.snapshot_fd.is_valid()) {
+    mappings->Share(kV8SnapshotDataDescriptor, v8_files_.snapshot_fd.get());
+#if defined(OS_ANDROID)
+    regions->insert(
+        std::make_pair(kV8SnapshotDataDescriptor, v8_files_.snapshot_region));
+#endif
+  }
 #endif  // V8_USE_EXTERNAL_STARTUP_DATA
 }
 #endif  // OS_POSIX && !OS_MACOSX
 
 content::ShellBrowserContext* ShellContentBrowserClient::browser_context() {
   return shell_browser_main_parts_->browser_context();
 }
 
 }  // namespace examples
 }  // namespace views