Add support to extension_shell and ash_shell to use external V8 snapshot files.

Adds support to extension_shell and ash_shell to use external V8 snapshot files
in preparation for moving ChromeOS and ChromeCast to use this.

Re-factors the chrome_content_browser_client and
content/shell_content_browser_client to allow more reuse
of the code which opens the V8 external snapshot for child processes
by adding IsolateHolder::OpenV8FilesForChildProcesses.

This does not yet switch ChromeOS to use external V8 snapshot files -
this will be done in follow up CL https://codereview.chromium.org/1019123002.

BUG=421063

Review URL: https://codereview.chromium.org/1019483002

Cr-Commit-Position: refs/heads/master@{#323953}

ash/shell/DEPS

 include_rules = [
   "+content/public",
   "+content/shell",
+  "+gin",
   "+sandbox",
 ]

ash/shell/content_client/shell_content_browser_client.cc

@@ -5,14 +5,21 @@
 #include "ash/shell/content_client/shell_content_browser_client.h"
 
 #include "ash/shell/content_client/shell_browser_main_parts.h"
+#include "content/public/common/content_descriptors.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_(NULL) {
+    :
+#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() {
@@ -34,6 +41,28 @@ net::URLRequestContextGetter* ShellContentBrowserClient::CreateRequestContext(
                                              request_interceptors.Pass());
 }
 
+#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 (v8_natives_fd_.get() == -1 || v8_snapshot_fd_.get() == -1) {
+    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);
+  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();
 }

ash/shell/content_client/shell_content_browser_client.h

@@ -33,10 +33,21 @@ class ShellContentBrowserClient : public content::ContentBrowserClient {
       content::BrowserContext* browser_context,
       content::ProtocolHandlerMap* protocol_handlers,
       content::URLRequestInterceptorScopedVector request_interceptors) override;
+#if defined(OS_POSIX) && !defined(OS_MACOSX)
+  void GetAdditionalMappedFilesForChildProcess(
+      const base::CommandLine& command_line,
+      int child_process_id,
+      content::FileDescriptorInfo* mappings) override;
+#endif
 
   content::ShellBrowserContext* browser_context();
 
  private:
+#if defined(OS_POSIX) && !defined(OS_MACOSX)
+  base::ScopedFD v8_natives_fd_;
+  base::ScopedFD v8_snapshot_fd_;
+#endif
+
   ShellBrowserMainParts* shell_browser_main_parts_;
 
   DISALLOW_COPY_AND_ASSIGN(ShellContentBrowserClient);

chrome/browser/chrome_content_browser_client.cc

@@ -2183,23 +2183,16 @@ void ChromeContentBrowserClient::GetAdditionalMappedFilesForChildProcess(
     int child_process_id,
     FileDescriptorInfo* mappings) {
 #if defined(V8_USE_EXTERNAL_STARTUP_DATA)
-  if (v8_snapshot_fd_.get() == -1 && v8_natives_fd_.get() == -1) {
-    base::FilePath v8_data_path;
-    PathService::Get(gin::V8Initializer::kV8SnapshotBasePathKey, &v8_data_path);
-    DCHECK(!v8_data_path.empty());
-
-    int file_flags = base::File::FLAG_OPEN | base::File::FLAG_READ;
-    base::FilePath v8_natives_data_path =
-        v8_data_path.AppendASCII(gin::V8Initializer::kNativesFileName);
-    base::FilePath v8_snapshot_data_path =
-        v8_data_path.AppendASCII(gin::V8Initializer::kSnapshotFileName);
-    base::File v8_natives_data_file(v8_natives_data_path, file_flags);
-    base::File v8_snapshot_data_file(v8_snapshot_data_path, file_flags);
-    DCHECK(v8_natives_data_file.IsValid());
-    DCHECK(v8_snapshot_data_file.IsValid());
-    v8_natives_fd_.reset(v8_natives_data_file.TakePlatformFile());
-    v8_snapshot_fd_.reset(v8_snapshot_data_file.TakePlatformFile());
+  if (v8_natives_fd_.get() == -1 || v8_snapshot_fd_.get() == -1) {
+    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);
   mappings->Share(kV8NativesDataDescriptor, v8_natives_fd_.get());
   mappings->Share(kV8SnapshotDataDescriptor, v8_snapshot_fd_.get());
 #endif  // V8_USE_EXTERNAL_STARTUP_DATA

content/shell/browser/shell_content_browser_client.cc

@@ -333,23 +333,16 @@ void ShellContentBrowserClient::GetAdditionalMappedFilesForChildProcess(
     int child_process_id,
     FileDescriptorInfo* mappings) {
 #if defined(V8_USE_EXTERNAL_STARTUP_DATA)
-  if (v8_snapshot_fd_.get() == -1 && v8_natives_fd_.get() == -1) {
-    base::FilePath v8_data_path;
-    PathService::Get(gin::V8Initializer::kV8SnapshotBasePathKey, &v8_data_path);
-    DCHECK(!v8_data_path.empty());
-
-    int file_flags = base::File::FLAG_OPEN | base::File::FLAG_READ;
-    base::FilePath v8_natives_data_path =
-        v8_data_path.AppendASCII(gin::V8Initializer::kNativesFileName);
-    base::FilePath v8_snapshot_data_path =
-        v8_data_path.AppendASCII(gin::V8Initializer::kSnapshotFileName);
-    base::File v8_natives_data_file(v8_natives_data_path, file_flags);
-    base::File v8_snapshot_data_file(v8_snapshot_data_path, file_flags);
-    DCHECK(v8_natives_data_file.IsValid());
-    DCHECK(v8_snapshot_data_file.IsValid());
-    v8_natives_fd_.reset(v8_natives_data_file.TakePlatformFile());
-    v8_snapshot_fd_.reset(v8_snapshot_data_file.TakePlatformFile());
+  if (v8_natives_fd_.get() == -1 || v8_snapshot_fd_.get() == -1) {
+    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);
   mappings->Share(kV8NativesDataDescriptor, v8_natives_fd_.get());
   mappings->Share(kV8SnapshotDataDescriptor, v8_snapshot_fd_.get());
 #endif  // V8_USE_EXTERNAL_STARTUP_DATA

extensions/shell/browser/DEPS

@@ -21,6 +21,8 @@ include_rules = [
   "+device/hid",
   "+device/usb",
 
+  "+gin",
+
   "+google_apis/gaia",
 
   "+net",

extensions/shell/browser/shell_content_browser_client.cc

@@ -8,6 +8,7 @@
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/site_instance.h"
+#include "content/public/common/content_descriptors.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/common/url_constants.h"
 #include "content/shell/browser/shell_browser_context.h"
@@ -26,6 +27,7 @@
 #include "extensions/shell/browser/shell_browser_main_parts.h"
 #include "extensions/shell/browser/shell_extension_system.h"
 #include "extensions/shell/browser/shell_speech_recognition_manager_delegate.h"
+#include "gin/v8_initializer.h"
 #include "url/gurl.h"
 
 #if !defined(DISABLE_NACL)
@@ -45,19 +47,25 @@ using content::BrowserThread;
 namespace extensions {
 namespace {
 
-ShellContentBrowserClient* g_instance = NULL;
+ShellContentBrowserClient* g_instance = nullptr;
 
 }  // namespace
 
 ShellContentBrowserClient::ShellContentBrowserClient(
     ShellBrowserMainDelegate* browser_main_delegate)
-    : browser_main_parts_(NULL), browser_main_delegate_(browser_main_delegate) {
+    :
+#if defined(OS_POSIX) && !defined(OS_MACOSX)
+      v8_natives_fd_(-1),
+      v8_snapshot_fd_(-1),
+#endif  // OS_POSIX && !OS_MACOSX
+      browser_main_parts_(nullptr),
+      browser_main_delegate_(browser_main_delegate) {
   DCHECK(!g_instance);
   g_instance = this;
 }
 
 ShellContentBrowserClient::~ShellContentBrowserClient() {
-  g_instance = NULL;
+  g_instance = nullptr;
 }
 
 // static
@@ -219,7 +227,7 @@ ShellContentBrowserClient::GetExternalBrowserPpapiHost(int plugin_process_id) {
     ++iter;
   }
 #endif
-  return NULL;
+  return nullptr;
 }
 
 void ShellContentBrowserClient::GetAdditionalAllowedSchemesForFileSystem(
@@ -229,6 +237,28 @@ void ShellContentBrowserClient::GetAdditionalAllowedSchemesForFileSystem(
   additional_allowed_schemes->push_back(kExtensionScheme);
 }
 
+#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 (v8_natives_fd_.get() == -1 || v8_snapshot_fd_.get() == -1) {
+    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);
+  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::DevToolsManagerDelegate*
 ShellContentBrowserClient::GetDevToolsManagerDelegate() {
   return new content::ShellDevToolsManagerDelegate(GetBrowserContext());

extensions/shell/browser/shell_content_browser_client.h

@@ -58,6 +58,13 @@ class ShellContentBrowserClient : public content::ContentBrowserClient {
       int plugin_process_id) override;
   void GetAdditionalAllowedSchemesForFileSystem(
       std::vector<std::string>* additional_schemes) override;
+#if defined(OS_POSIX) && !defined(OS_MACOSX)
+  void GetAdditionalMappedFilesForChildProcess(
+      const base::CommandLine& command_line,
+      int child_process_id,
+      content::FileDescriptorInfo* mappings) override;
+#endif
+
   content::DevToolsManagerDelegate* GetDevToolsManagerDelegate() override;
 
  protected:
@@ -73,6 +80,11 @@ class ShellContentBrowserClient : public content::ContentBrowserClient {
   // Returns the extension or app associated with |site_instance| or NULL.
   const Extension* GetExtension(content::SiteInstance* site_instance);
 
+#if defined(OS_POSIX) && !defined(OS_MACOSX)
+  base::ScopedFD v8_natives_fd_;
+  base::ScopedFD v8_snapshot_fd_;
+#endif
+
   // Owned by content::BrowserMainLoop.
   ShellBrowserMainParts* browser_main_parts_;
 

gin/v8_initializer.cc

@@ -24,15 +24,47 @@ namespace gin {
 
 namespace {
 
-bool GenerateEntropy(unsigned char* buffer, size_t amount) {
-  base::RandBytes(buffer, amount);
-  return true;
-}
-
 base::MemoryMappedFile* g_mapped_natives = nullptr;
 base::MemoryMappedFile* g_mapped_snapshot = nullptr;
 
 #if defined(V8_USE_EXTERNAL_STARTUP_DATA)
+#if !defined(OS_MACOSX)
+const int kV8SnapshotBasePathKey =
+#if defined(OS_ANDROID)
+    base::DIR_ANDROID_APP_DATA;
+#elif defined(OS_POSIX)
+    base::DIR_EXE;
+#elif defined(OS_WIN)
+    base::DIR_MODULE;
+#endif  // OS_ANDROID
+#endif  // !OS_MACOSX
+
+const char kNativesFileName[] = "natives_blob.bin";
+const char kSnapshotFileName[] = "snapshot_blob.bin";
+
+void GetV8FilePaths(base::FilePath* natives_path_out,
+                    base::FilePath* snapshot_path_out) {
+#if !defined(OS_MACOSX)
+  base::FilePath data_path;
+  PathService::Get(kV8SnapshotBasePathKey, &data_path);
+  DCHECK(!data_path.empty());
+
+  *natives_path_out = data_path.AppendASCII(kNativesFileName);
+  *snapshot_path_out = data_path.AppendASCII(kSnapshotFileName);
+#else   // !defined(OS_MACOSX)
+  base::ScopedCFTypeRef<CFStringRef> natives_file_name(
+      base::SysUTF8ToCFStringRef(kNativesFileName));
+  *natives_path_out =
+      base::mac::PathForFrameworkBundleResource(natives_file_name);
+  base::ScopedCFTypeRef<CFStringRef> snapshot_file_name(
+      base::SysUTF8ToCFStringRef(kSnapshotFileName));
+  *snapshot_path_out =
+      base::mac::PathForFrameworkBundleResource(snapshot_file_name);
+  DCHECK(!natives_path_out->empty());
+  DCHECK(!snapshot_path_out->empty());
+#endif  // !defined(OS_MACOSX)
+}
+
 bool MapV8Files(base::File natives_file,
                 base::File snapshot_file,
                 base::MemoryMappedFile::Region natives_region =
@@ -75,58 +107,32 @@ bool VerifyV8SnapshotFile(base::MemoryMappedFile* snapshot_file,
 #endif  // V8_VERIFY_EXTERNAL_STARTUP_DATA
 #endif  // V8_USE_EXTERNAL_STARTUP_DATA
 
+bool GenerateEntropy(unsigned char* buffer, size_t amount) {
+  base::RandBytes(buffer, amount);
+  return true;
+}
+
 }  // namespace
 
 #if defined(V8_USE_EXTERNAL_STARTUP_DATA)
-
 #if defined(V8_VERIFY_EXTERNAL_STARTUP_DATA)
 // Defined in gen/gin/v8_snapshot_fingerprint.cc
 extern const unsigned char g_natives_fingerprint[];
 extern const unsigned char g_snapshot_fingerprint[];
 #endif  // V8_VERIFY_EXTERNAL_STARTUP_DATA
 
-#if !defined(OS_MACOSX)
-const int V8Initializer::kV8SnapshotBasePathKey =
-#if defined(OS_ANDROID)
-    base::DIR_ANDROID_APP_DATA;
-#elif defined(OS_POSIX)
-    base::DIR_EXE;
-#elif defined(OS_WIN)
-    base::DIR_MODULE;
-#endif  // OS_ANDROID
-#endif  // !OS_MACOSX
-
-const char V8Initializer::kNativesFileName[] = "natives_blob.bin";
-const char V8Initializer::kSnapshotFileName[] = "snapshot_blob.bin";
-
 // static
 bool V8Initializer::LoadV8Snapshot() {
   if (g_mapped_natives && g_mapped_snapshot)
     return true;
 
-#if !defined(OS_MACOSX)
-  base::FilePath data_path;
-  PathService::Get(kV8SnapshotBasePathKey, &data_path);
-  DCHECK(!data_path.empty());
-
-  base::FilePath natives_path = data_path.AppendASCII(kNativesFileName);
-  base::FilePath snapshot_path = data_path.AppendASCII(kSnapshotFileName);
-#else   // !defined(OS_MACOSX)
-  base::ScopedCFTypeRef<CFStringRef> natives_file_name(
-      base::SysUTF8ToCFStringRef(kNativesFileName));
-  base::FilePath natives_path =
-      base::mac::PathForFrameworkBundleResource(natives_file_name);
-  base::ScopedCFTypeRef<CFStringRef> snapshot_file_name(
-      base::SysUTF8ToCFStringRef(kSnapshotFileName));
-  base::FilePath snapshot_path =
-      base::mac::PathForFrameworkBundleResource(snapshot_file_name);
-  DCHECK(!natives_path.empty());
-  DCHECK(!snapshot_path.empty());
-#endif  // !defined(OS_MACOSX)
+  base::FilePath natives_data_path;
+  base::FilePath snapshot_data_path;
+  GetV8FilePaths(&natives_data_path, &snapshot_data_path);
 
   int flags = base::File::FLAG_OPEN | base::File::FLAG_READ;
-  if (!MapV8Files(base::File(natives_path, flags),
-                  base::File(snapshot_path, flags)))
+  if (!MapV8Files(base::File(natives_data_path, flags),
+                  base::File(snapshot_data_path, flags)))
     return false;
 
 #if defined(V8_VERIFY_EXTERNAL_STARTUP_DATA)
@@ -165,6 +171,26 @@ bool V8Initializer::LoadV8SnapshotFromFD(base::PlatformFile natives_pf,
                     natives_region, snapshot_region);
 }
 
+// static
+bool V8Initializer::OpenV8FilesForChildProcesses(
+    base::PlatformFile* natives_fd_out,
+    base::PlatformFile* snapshot_fd_out) {
+  base::FilePath natives_data_path;
+  base::FilePath snapshot_data_path;
+  GetV8FilePaths(&natives_data_path, &snapshot_data_path);
+
+  int file_flags = base::File::FLAG_OPEN | base::File::FLAG_READ;
+  base::File natives_data_file(natives_data_path, file_flags);
+  base::File snapshot_data_file(snapshot_data_path, file_flags);
+
+  if (!natives_data_file.IsValid() || !snapshot_data_file.IsValid())
+    return false;
+
+  *natives_fd_out = natives_data_file.TakePlatformFile();
+  *snapshot_fd_out = snapshot_data_file.TakePlatformFile();
+  return true;
+}
+
 #endif  // V8_USE_EXTERNAL_STARTUP_DATA
 
 // static

gin/v8_initializer.h

@@ -49,6 +49,12 @@ class GIN_EXPORT V8Initializer {
   // snapshot is already loaded, false otherwise.
   static bool LoadV8Snapshot();
 
+  // Opens the V8 snapshot data files and returns open file descriptors to these
+  // files in |natives_fd_out| and |snapshot_fd_out|, which can be passed to
+  // child processes.
+  static bool OpenV8FilesForChildProcesses(base::PlatformFile* natives_fd_out,
+                                           base::PlatformFile* snapshot_fd_out);
+
 #endif  // V8_USE_EXTERNAL_STARTUP_DATA
 };