Infrastructure for enabling V8's initial snapshot to be loaded from external files as opposed to being statically linked to the binary.

This is not currently supported on any architecture.

BUG=421063

Review URL: https://codereview.chromium.org/594603003

Cr-Commit-Position: refs/heads/master@{#301595}

52 files changed, 495 insertions, 19 deletions

diff --git a/android_webview/android_webview_tests.gypi b/android_webview/android_webview_tests.gypi
index d775cc9..9ef2289 100644
--- a/android_webview/android_webview_tests.gypi
+++ b/android_webview/android_webview_tests.gypi
@@ -35,6 +35,12 @@
               '<(PRODUCT_DIR)/icudtl.dat',
             ],
           }],
+          ['v8_use_external_startup_data==1', {
+            'additional_input_paths': [
+              '<(PRODUCT_DIR)/natives_blob.bin',
+              '<(PRODUCT_DIR)/snapshot_blob.bin',
+            ],
+          }],
         ],
       },
       'copies': [
@@ -55,7 +61,13 @@
               'files': [
                 '<(PRODUCT_DIR)/icudtl.dat',
               ],
-	    }],
+            }],
+            ['v8_use_external_startup_data==1', {
+              'files': [
+                '<(PRODUCT_DIR)/natives_blob.bin',
+                '<(PRODUCT_DIR)/snapshot_blob.bin',
+              ],
+            }],
           ],
         },
       ],
diff --git a/android_webview/test/shell/src/org/chromium/android_webview/shell/AwShellApplication.java b/android_webview/test/shell/src/org/chromium/android_webview/shell/AwShellApplication.java
index 46276ab..62158ff 100644
--- a/android_webview/test/shell/src/org/chromium/android_webview/shell/AwShellApplication.java
+++ b/android_webview/test/shell/src/org/chromium/android_webview/shell/AwShellApplication.java
@@ -21,7 +21,9 @@ public class AwShellApplication extends Application {
 
     private static final String TAG = "AwShellApplication";
     /** The minimum set of .pak files the test runner needs. */
-    private static final String[] MANDATORY_PAKS = { "icudtl.dat" };
+    private static final String[] MANDATORY_PAKS = { "icudtl.dat",
+                                                     "natives_blob.bin",
+                                                     "snapshot_blob.bin" };
 
     @Override
     public void onCreate() {
diff --git a/base/android/java/src/org/chromium/base/ResourceExtractor.java b/base/android/java/src/org/chromium/base/ResourceExtractor.java
index 4cf155c..37fea6c 100644
--- a/base/android/java/src/org/chromium/base/ResourceExtractor.java
+++ b/base/android/java/src/org/chromium/base/ResourceExtractor.java
@@ -36,6 +36,8 @@ public class ResourceExtractor {
     private static final String LAST_LANGUAGE = "Last language";
     private static final String PAK_FILENAMES = "Pak filenames";
     private static final String ICU_DATA_FILENAME = "icudtl.dat";
+    private static final String V8_NATIVES_DATA_FILENAME = "natives_blob.bin";
+    private static final String V8_SNAPSHOT_DATA_FILENAME = "snapshot_blob.bin";
 
     private static String[] sMandatoryPaks = null;
 
@@ -111,8 +113,11 @@ public class ResourceExtractor {
                     if (!paksToInstall.matcher(file).matches()) {
                         continue;
                     }
-                    boolean isICUData = file.equals(ICU_DATA_FILENAME);
-                    File output = new File(isICUData ? getAppDataDir() : outputDir, file);
+                    boolean isAppDataFile = file.equals(ICU_DATA_FILENAME)
+                                      || file.equals(V8_NATIVES_DATA_FILENAME)
+                                      || file.equals(V8_SNAPSHOT_DATA_FILENAME);
+                    File output = new File(isAppDataFile
+                                           ? getAppDataDir() : outputDir, file);
                     if (output.exists()) {
                         continue;
                     }
@@ -138,10 +143,11 @@ public class ResourceExtractor {
                             throw new IOException(file + " extracted with 0 length!");
                         }
 
-                        if (!isICUData) {
+                        if (!isAppDataFile) {
                             filenames.add(file);
                         } else {
-                            // icudata needs to be accessed by a renderer process.
+                            // icu and V8 data need to be accessed by a renderer
+                            // process.
                             output.setReadable(true, false);
                         }
                     } finally {
@@ -274,18 +280,21 @@ public class ResourceExtractor {
      * running the tests.
      */
     @VisibleForTesting
-    public void setExtractAllPaksForTesting() {
-        List<String> pakFileAssets = new ArrayList<String>();
+    public void setExtractAllPaksAndV8SnapshotForTesting() {
+        List<String> pakAndSnapshotFileAssets = new ArrayList<String>();
         AssetManager manager = mContext.getResources().getAssets();
         try {
             String[] files = manager.list("");
             for (String file : files) {
-                if (file.endsWith(".pak")) pakFileAssets.add(file);
+                if (file.endsWith(".pak")) pakAndSnapshotFileAssets.add(file);
             }
         } catch (IOException e) {
             Log.w(LOGTAG, "Exception while accessing assets: " + e.getMessage(), e);
         }
-        setMandatoryPaksToExtract(pakFileAssets.toArray(new String[pakFileAssets.size()]));
+        pakAndSnapshotFileAssets.add("natives_blob.bin");
+        pakAndSnapshotFileAssets.add("snapshot_blob.bin");
+        setMandatoryPaksToExtract(pakAndSnapshotFileAssets.toArray(
+                new String[pakAndSnapshotFileAssets.size()]));
     }
 
     private ResourceExtractor(Context context) {
@@ -340,15 +349,27 @@ public class ResourceExtractor {
     /**
      * Pak files (UI strings and other resources) should be updated along with
      * Chrome. A version mismatch can lead to a rather broken user experience.
-     * The ICU data (icudtl.dat) is less version-sensitive, but still can
-     * lead to malfunction/UX misbehavior. So, we regard failing to update them
-     * as an error.
+     * Failing to update the V8 snapshot files will lead to a version mismatch
+     * between V8 and the loaded snapshot which will cause V8 to crash, so this
+     * is treated as an error. The ICU data (icudtl.dat) is less
+     * version-sensitive, but still can lead to malfunction/UX misbehavior. So,
+     * we regard failing to update them as an error.
      */
     private void deleteFiles() {
         File icudata = new File(getAppDataDir(), ICU_DATA_FILENAME);
         if (icudata.exists() && !icudata.delete()) {
             Log.e(LOGTAG, "Unable to remove the icudata " + icudata.getName());
         }
+        File v8_natives = new File(getAppDataDir(), V8_NATIVES_DATA_FILENAME);
+        if (v8_natives.exists() && !v8_natives.delete()) {
+            Log.e(LOGTAG,
+                    "Unable to remove the v8 data " + v8_natives.getName());
+        }
+        File v8_snapshot = new File(getAppDataDir(), V8_SNAPSHOT_DATA_FILENAME);
+        if (v8_snapshot.exists() && !v8_snapshot.delete()) {
+            Log.e(LOGTAG,
+                    "Unable to remove the v8 data " + v8_snapshot.getName());
+        }
         File dir = getOutputDir();
         if (dir.exists()) {
             File[] files = dir.listFiles();
diff --git a/build/android/pylib/gtest/setup.py b/build/android/pylib/gtest/setup.py
index c3af91f..5581fbc 100644
--- a/build/android/pylib/gtest/setup.py
+++ b/build/android/pylib/gtest/setup.py
@@ -122,6 +122,7 @@ def _GenerateDepsDirUsingIsolate(suite_name, isolate_file_path=None):
       '--config-variable', 'fastbuild', '0',
       '--config-variable', 'icu_use_data_file_flag', '1',
       '--config-variable', 'libpeer_target_type', 'static_library',
+      '--config-variable', 'v8_use_external_startup_data', '0',
       '--config-variable', 'lsan', '0',
       # TODO(maruel): This may not be always true.
       '--config-variable', 'target_arch', 'arm',
diff --git a/build/common.gypi b/build/common.gypi
index dcba6de..ffcf4aa 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -1004,6 +1004,14 @@
         }, {
           'optimize_jni_generation%': 0,
         }],
+
+        # TODO(baixo): Enable v8_use_external_startup_data
+        # http://crbug.com/421063
+        ['android_webview_build==0 and android_webview_telemetry_build==0 and chromecast==0', {
+          'v8_use_external_startup_data': 0,
+        }, {
+          'v8_use_external_startup_data': 0,
+        }],
       ],
 
       # Set this to 1 to enable use of concatenated impulse responses
@@ -1205,6 +1213,7 @@
     'video_hole%': '<(video_hole)',
     'enable_load_completion_hacks%': '<(enable_load_completion_hacks)',
     'support_pre_M6_history_database%': '<(support_pre_M6_history_database)',
+    'v8_use_external_startup_data': '<(v8_use_external_startup_data)',
 
     # Whether or not we are building the Athena shell.
     'use_athena%': '0',
@@ -2925,6 +2934,9 @@
       ['enable_load_completion_hacks==1', {
         'defines': ['ENABLE_LOAD_COMPLETION_HACKS=1'],
       }],
+      ['v8_use_external_startup_data==1', {
+       'defines': ['V8_USE_EXTERNAL_STARTUP_DATA'],
+      }],
     ],  # conditions for 'target_defaults'
     'target_conditions': [
       ['<(use_openssl)==1', {
diff --git a/build/isolate.gypi b/build/isolate.gypi
index 17bf3c7..467bdaa 100644
--- a/build/isolate.gypi
+++ b/build/isolate.gypi
@@ -85,6 +85,7 @@
         '--config-variable',
           'internal_gles2_conform_tests=<(internal_gles2_conform_tests)',
         '--config-variable', 'icu_use_data_file_flag=<(icu_use_data_file_flag)',
+        '--config-variable', 'v8_use_external_startup_data=<(v8_use_external_startup_data)',
         '--config-variable', 'lsan=<(lsan)',
         '--config-variable', 'libpeer_target_type=<(libpeer_target_type)',
         '--config-variable', 'use_openssl=<(use_openssl)',
diff --git a/chrome/android/shell/java/src/org/chromium/chrome/shell/ChromeShellApplication.java b/chrome/android/shell/java/src/org/chromium/chrome/shell/ChromeShellApplication.java
index 17ae832..9df9aea 100644
--- a/chrome/android/shell/java/src/org/chromium/chrome/shell/ChromeShellApplication.java
+++ b/chrome/android/shell/java/src/org/chromium/chrome/shell/ChromeShellApplication.java
@@ -31,12 +31,18 @@ public class ChromeShellApplication extends ChromiumApplication {
      * for its operation. We used to link the data statically to our binary,
      * but don't do that any more and need to install along with pak files.
      * See src/third_party/icu/README.chromium.
+     *
+     *  V8's initial snapshot used to be statically linked to the binary, but
+     *  now it's loaded from external files. Therefore we need to install such
+     *  snapshots (natives_blob.bin and snapshot.bin) along with pak files.
      */
     private static final String[] CHROME_MANDATORY_PAKS = {
         "en-US.pak",
         "resources.pak",
         "chrome_100_percent.pak",
         "icudtl.dat",
+        "natives_blob.bin",
+        "snapshot_blob.bin"
     };
     private static final String COMMAND_LINE_FILE = "/data/local/tmp/chrome-shell-command-line";
 
diff --git a/chrome/browser/chrome_content_browser_client.cc b/chrome/browser/chrome_content_browser_client.cc
index 446e560a..f7fd810 100644
--- a/chrome/browser/chrome_content_browser_client.cc
+++ b/chrome/browser/chrome_content_browser_client.cc
@@ -2503,6 +2503,26 @@ void ChromeContentBrowserClient::GetAdditionalMappedFilesForChildProcess(
   mappings->Transfer(kAndroidICUDataDescriptor,
                      base::ScopedFD(icudata_file.TakePlatformFile()));
 
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA
+  base::FilePath v8_data_path;
+  PathService::Get(base::DIR_ANDROID_APP_DATA, &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("natives_blob.bin");
+  base::FilePath v8_snapshot_data_path =
+      v8_data_path.AppendASCII("snapshot_blob.bin");
+  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());
+  mappings->Transfer(kV8NativesDataDescriptor,
+                     base::ScopedFD(v8_natives_data_file.TakePlatformFile()));
+  mappings->Transfer(kV8SnapshotDataDescriptor,
+                     base::ScopedFD(v8_snapshot_data_file.TakePlatformFile()));
+#endif  // V8_USE_EXTERNAL_STARTUP_DATA
+
 #else
   int crash_signal_fd = GetCrashSignalFD(command_line);
   if (crash_signal_fd >= 0) {
diff --git a/chrome/browser/resources/chromeos/chromevox/chromevox_tests.gypi b/chrome/browser/resources/chromeos/chromevox/chromevox_tests.gypi
index c4a1e9a..e9c9f61 100644
--- a/chrome/browser/resources/chromeos/chromevox/chromevox_tests.gypi
+++ b/chrome/browser/resources/chromeos/chromevox/chromevox_tests.gypi
@@ -45,6 +45,15 @@
           'rule_name': 'js2webui',
           'extension': 'unitjs',
           'msvs_external_rule': 1,
+          'variables': {
+            'conditions': [
+              ['v8_use_external_startup_data==1', {
+                'external_v8': 'y',
+              }, {
+                'external_v8': 'n',
+              }],
+            ],
+          },
           'inputs': [
             '<(gypv8sh)',
             '<(PRODUCT_DIR)/d8<(EXECUTABLE_SUFFIX)',
@@ -65,6 +74,7 @@
             '<(gypv8sh)',
             '<(PRODUCT_DIR)/d8<(EXECUTABLE_SUFFIX)',
             '--deps_js', '<(chromevox_test_deps_js_file)',
+            '--external', '<(external_v8)',
             '<(mock_js)',
             '<(test_api_js)',
             '<(js2gtest)',
@@ -80,6 +90,15 @@
           'rule_name': 'js2extension',
           'extension': 'extjs',
           'msvs_external_rule': 1,
+          'variables': {
+            'conditions': [
+              ['v8_use_external_startup_data==1', {
+                'external_v8': 'y',
+              }, {
+                'external_v8': 'n',
+              }],
+            ],
+          },
           'inputs': [
             '<(gypv8sh)',
             '<(PRODUCT_DIR)/d8<(EXECUTABLE_SUFFIX)',
@@ -98,6 +117,7 @@
             'python',
             '<(gypv8sh)',
             '<(PRODUCT_DIR)/d8<(EXECUTABLE_SUFFIX)',
+            '--external', '<(external_v8)',
             '<(mock_js)',
             '<(test_api_js)',
             '<(js2gtest)',
diff --git a/chrome/chrome.isolate b/chrome/chrome.isolate
index 5457f64..54e18dc 100644
--- a/chrome/chrome.isolate
+++ b/chrome/chrome.isolate
@@ -94,5 +94,6 @@
   ],
   'includes': [
     'angle.isolate',
+    '../gin/v8.isolate',
   ],
 }
diff --git a/chrome/chrome_android_paks.gypi b/chrome/chrome_android_paks.gypi
index 90f0238..574d5cc 100644
--- a/chrome/chrome_android_paks.gypi
+++ b/chrome/chrome_android_paks.gypi
@@ -109,6 +109,16 @@
           '<(chrome_android_pak_output_folder)/icudtl.dat',
         ],
       }],
+      ['v8_use_external_startup_data==1', {
+        'chrome_android_pak_input_resources': [
+          '<(PRODUCT_DIR)/natives_blob.bin',
+          '<(PRODUCT_DIR)/snapshot_blob.bin',
+        ],
+        'chrome_android_pak_output_resources': [
+          '<(chrome_android_pak_output_folder)/natives_blob.bin',
+          '<(chrome_android_pak_output_folder)/snapshot_blob.bin',
+        ],
+      }],
     ],
   },
 }
diff --git a/chrome/chrome_tests.gypi b/chrome/chrome_tests.gypi
index 7822385..d89d00b 100644
--- a/chrome/chrome_tests.gypi
+++ b/chrome/chrome_tests.gypi
@@ -1880,6 +1880,15 @@
           'rule_name': 'js2webui',
           'extension': 'js',
           'msvs_external_rule': 1,
+          'variables': {
+            'conditions': [
+              ['v8_use_external_startup_data==1', {
+                'external_v8': 'y',
+              }, {
+                'external_v8': 'n',
+              }],
+            ],
+          },
           'inputs': [
             '<(gypv8sh)',
             '<(PRODUCT_DIR)/d8<(EXECUTABLE_SUFFIX)',
@@ -1895,6 +1904,7 @@
           'action': [
             'python',
             '<@(_inputs)',
+            '--external', '<(external_v8)',
             'webui',
             '<(RULE_INPUT_PATH)',
             'chrome/<(RULE_INPUT_DIRNAME)/<(RULE_INPUT_ROOT).js',
@@ -2450,6 +2460,15 @@
           'rule_name': 'js2webui',
           'extension': 'js',
           'msvs_external_rule': 1,
+          'variables': {
+            'conditions': [
+              ['v8_use_external_startup_data==1', {
+                'external_v8': 'y',
+              }, {
+                'external_v8': 'n',
+              }],
+            ],
+          },
           'inputs': [
             '<(gypv8sh)',
             '<(PRODUCT_DIR)/d8<(EXECUTABLE_SUFFIX)',
@@ -2466,6 +2485,7 @@
             'python',
             '<@(_inputs)',
             'webui',
+            '--external', '<(external_v8)',
             '<(RULE_INPUT_PATH)',
             'chrome/<(RULE_INPUT_DIRNAME)/<(RULE_INPUT_ROOT).js',
             '<@(_outputs)',
diff --git a/chrome/chrome_tests_unit.gypi b/chrome/chrome_tests_unit.gypi
index c98c284..8457225 100644
--- a/chrome/chrome_tests_unit.gypi
+++ b/chrome/chrome_tests_unit.gypi
@@ -2851,6 +2851,23 @@
           'variables': {
             'test_suite_name': 'unit_tests',
             'android_manifest_path': 'test/android/unit_tests_apk/AndroidManifest.xml',
+            'conditions': [
+              ['v8_use_external_startup_data==1', {
+                'additional_input_paths': [
+                  '<(PRODUCT_DIR)/natives_blob.bin',
+                  '<(PRODUCT_DIR)/snapshot_blob.bin',
+                ],
+                'copies': [
+                  {
+                    'destination': '<(PRODUCT_DIR)/unit_tests_apk/assets',
+                    'files': [
+                      '<(PRODUCT_DIR)/natives_blob.bin',
+                      '<(PRODUCT_DIR)/snapshot_blob.bin',
+                    ],
+                  },
+                ],
+              }],
+            ],
           },
           'includes': [ '../build/apk_test.gypi' ],
         },
diff --git a/chrome/installer/mini_installer.gyp b/chrome/installer/mini_installer.gyp
index c2bb835..e6b0ca7 100644
--- a/chrome/installer/mini_installer.gyp
+++ b/chrome/installer/mini_installer.gyp
@@ -224,6 +224,12 @@
                     '<(PRODUCT_DIR)/icudtl.dat',
                   ],
                 }],
+                ['v8_use_external_startup_data == 1', {
+                  'inputs': [
+                    '<(PRODUCT_DIR)/natives_blob.bin',
+                    '<(PRODUCT_DIR)/snapshot_blob.bin',
+                  ],
+                }],
               ],
               'inputs': [
                 '<(create_installer_archive_py_path)',
diff --git a/chrome/interactive_ui_tests.isolate b/chrome/interactive_ui_tests.isolate
index df3893d..066c007 100644
--- a/chrome/interactive_ui_tests.isolate
+++ b/chrome/interactive_ui_tests.isolate
@@ -122,5 +122,6 @@
   ],
   'includes': [
     '../base/base.isolate',
+    '../gin/v8.isolate',
   ],
 }
diff --git a/chrome/js_unittest_rules.gypi b/chrome/js_unittest_rules.gypi
index 27901f1c..b3dff9c 100644
--- a/chrome/js_unittest_rules.gypi
+++ b/chrome/js_unittest_rules.gypi
@@ -54,6 +54,15 @@
       'rule_name': 'js2unit',
       'extension': 'gtestjs',
       'msvs_external_rule': 1,
+      'variables': {
+        'conditions': [
+          ['v8_use_external_startup_data==1', {
+            'external_v8': 'y',
+          }, {
+            'external_v8': 'n',
+          }],
+        ],
+      },
       'inputs': [
         '<(gypv8sh)',
         '<(PRODUCT_DIR)/d8<(EXECUTABLE_SUFFIX)',
@@ -69,6 +78,7 @@
       'action': [
         'python',
         '<@(_inputs)',
+        '--external', '<(external_v8)',
         'unit',
         '<(RULE_INPUT_PATH)',
         'chrome/<(RULE_INPUT_DIRNAME)/<(RULE_INPUT_ROOT).<(_extension)',
diff --git a/chrome/sync_integration_tests.isolate b/chrome/sync_integration_tests.isolate
index 4c01825..3c5e0e1 100644
--- a/chrome/sync_integration_tests.isolate
+++ b/chrome/sync_integration_tests.isolate
@@ -98,5 +98,6 @@
   ],
   'includes': [
     '../base/base.isolate',
+    '../gin/v8.isolate',
   ],
 }
diff --git a/chrome/unit_tests.isolate b/chrome/unit_tests.isolate
index 2a5814f..a78618a 100644
--- a/chrome/unit_tests.isolate
+++ b/chrome/unit_tests.isolate
@@ -139,5 +139,6 @@
   ],
   'includes': [
     '../base/base.isolate',
+    '../gin/v8.isolate',
   ],
 }
diff --git a/components/components_unittests.isolate b/components/components_unittests.isolate
index 4d83010..a284dc1 100644
--- a/components/components_unittests.isolate
+++ b/components/components_unittests.isolate
@@ -17,5 +17,6 @@
   ],
   'includes': [
     '../third_party/icu/icu.isolate',
+    '../gin/v8.isolate',
   ],
 }
diff --git a/components/nacl_loader_unittests.isolate b/components/nacl_loader_unittests.isolate
index bdb01e0..51bb35c 100644
--- a/components/nacl_loader_unittests.isolate
+++ b/components/nacl_loader_unittests.isolate
@@ -17,5 +17,6 @@
   ],
   'includes': [
     '../sandbox/sandbox_linux_unittests.isolate',
+    '../gin/v8.isolate',
   ],
 }
diff --git a/content/app/DEPS b/content/app/DEPS
index 321c9ff..1fbfcab 100644
--- a/content/app/DEPS
+++ b/content/app/DEPS
@@ -1,4 +1,6 @@
 include_rules = [
   "+content",
+  # For loading V8's initial snapshot from external files.
+  "+gin/public/isolate_holder.h",
   "+media/base",  # For initializing media library.
 ]
diff --git a/content/app/content_main_runner.cc b/content/app/content_main_runner.cc
index 9031eef..05e45bd 100644
--- a/content/app/content_main_runner.cc
+++ b/content/app/content_main_runner.cc
@@ -50,6 +50,10 @@
 #include "ui/base/ui_base_paths.h"
 #include "ui/base/ui_base_switches.h"
 
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA
+#include "gin/public/isolate_holder.h"
+#endif
+
 #if defined(OS_ANDROID)
 #include "content/public/common/content_descriptors.h"
 #endif
@@ -716,9 +720,26 @@ class ContentMainRunnerImpl : public ContentMainRunner {
       CHECK(base::i18n::InitializeICUWithFileDescriptor(icudata_fd));
     else
       CHECK(base::i18n::InitializeICU());
+
+#ifdef 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) {
+      CHECK(gin::IsolateHolder::LoadV8SnapshotFD(v8_natives_fd,
+                                                 v8_snapshot_fd));
+    } else {
+      CHECK(gin::IsolateHolder::LoadV8Snapshot());
+    }
+#endif // V8_USE_EXTERNAL_STARTUP_DATA
+
 #else
     CHECK(base::i18n::InitializeICU());
-#endif
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA
+    CHECK(gin::IsolateHolder::LoadV8Snapshot());
+#endif // V8_USE_EXTERNAL_STARTUP_DATA
+#endif // OS_ANDROID
 
     InitializeStatsTable(command_line);
 
diff --git a/content/content.gyp b/content/content.gyp
index 5d843b64..6957c4c 100644
--- a/content/content.gyp
+++ b/content/content.gyp
@@ -575,6 +575,23 @@
             }],
           ],
         },
+        {
+          'target_name': 'content_v8_external_data',
+          'type': 'none',
+          'conditions': [
+            ['v8_use_external_startup_data==1', {
+              'copies': [
+                {
+                  'destination': '<(PRODUCT_DIR)/content_shell/assets',
+                  'files': [
+                    '<(PRODUCT_DIR)/natives_blob.bin',
+                    '<(PRODUCT_DIR)/snapshot_blob.bin',
+                  ],
+                },
+              ],
+            }],
+          ],
+        },
       ],
     }],  # OS == "android"
   ],
diff --git a/content/content_browsertests.isolate b/content/content_browsertests.isolate
index ea3cf07..53a53fc 100644
--- a/content/content_browsertests.isolate
+++ b/content/content_browsertests.isolate
@@ -124,5 +124,6 @@
   ],
   'includes': [
     '../base/base.isolate',
+    '../gin/v8.isolate',
   ],
 }
diff --git a/content/content_gl_tests.isolate b/content/content_gl_tests.isolate
index d5ff6d7..a9ca4e3 100644
--- a/content/content_gl_tests.isolate
+++ b/content/content_gl_tests.isolate
@@ -52,5 +52,6 @@
   ],
   'includes': [
     '../base/base.isolate',
+    '../gin/v8.isolate',
   ],
 }
diff --git a/content/content_shell.gypi b/content/content_shell.gypi
index e98d570..a3e8112 100644
--- a/content/content_shell.gypi
+++ b/content/content_shell.gypi
@@ -1050,6 +1050,7 @@
           'dependencies': [
             'content.gyp:content_icudata',
             'content.gyp:content_java',
+            'content.gyp:content_v8_external_data',
             'content_java_test_support',
             'content_shell_java',
             'libcontent_shell_content_view',
@@ -1075,6 +1076,12 @@
                   '<(PRODUCT_DIR)/icudtl.dat',
                 ],
               }],
+              ['v8_use_external_startup_data==1', {
+                'additional_input_paths': [
+                  '<(PRODUCT_DIR)/natives_blob.bin',
+                  '<(PRODUCT_DIR)/snapshot_blob.bin',
+                ],
+              }],
             ],
           },
           'conditions': [
diff --git a/content/content_tests.gypi b/content/content_tests.gypi
index ab604b4..03c64ce 100644
--- a/content/content_tests.gypi
+++ b/content/content_tests.gypi
@@ -337,7 +337,9 @@
         }],
         ['OS=="android"', {
           'dependencies': [
+            '../gin/gin.gyp:gin',
             '../ui/shell_dialogs/shell_dialogs.gyp:shell_dialogs',
+            'content.gyp:content_v8_external_data',
           ],
         }],
       ],
@@ -1633,6 +1635,23 @@
           ],
           'variables': {
             'test_suite_name': 'content_unittests',
+            'conditions': [
+              ['v8_use_external_startup_data==1', {
+                'additional_input_paths': [
+                  '<(PRODUCT_DIR)/natives_blob.bin',
+                  '<(PRODUCT_DIR)/snapshot_blob.bin',
+                ],
+                'copies': [
+                  {
+                    'destination': '<(PRODUCT_DIR)/content_unittests_apk/assets',
+                    'files': [
+                      '<(PRODUCT_DIR)/natives_blob.bin',
+                      '<(PRODUCT_DIR)/snapshot_blob.bin',
+                    ],
+                  },
+                ],
+              }],
+            ],
           },
           'includes': [ '../build/apk_test.gypi' ],
         },
@@ -1643,6 +1662,7 @@
           'dependencies': [
             'content.gyp:content_icudata',
             'content.gyp:content_java',
+            'content.gyp:content_v8_external_data',
             'content_browsertests',
             'content_java_test_support',
             'content_shell_java',
@@ -1660,6 +1680,12 @@
                   '<(PRODUCT_DIR)/icudtl.dat',
                 ],
               }],
+              ['v8_use_external_startup_data==1', {
+                'additional_input_paths': [
+                  '<(PRODUCT_DIR)/natives_blob.bin',
+                  '<(PRODUCT_DIR)/snapshot_blob.bin',
+                ],
+              }],
             ],
           },
           'includes': [ '../build/java_apk.gypi' ],
@@ -1687,6 +1713,7 @@
                 'chromium_android_linker_test',
                 'content.gyp:content_icudata',
                 'content.gyp:content_java',
+                'content.gyp:content_v8_external_data',
                 'content_shell_java',
               ],
               'variables': {
@@ -1704,6 +1731,12 @@
                       '<(PRODUCT_DIR)/icudtl.dat',
                     ],
                   }],
+                  ['v8_use_external_startup_data==1', {
+                    'additional_input_paths': [
+                      '<(PRODUCT_DIR)/natives_blob.bin',
+                      '<(PRODUCT_DIR)/snapshot_blob.bin',
+                    ],
+                  }],
                 ],
               },
               'includes': [ '../build/java_apk.gypi' ],
diff --git a/content/content_unittests.isolate b/content/content_unittests.isolate
index 184f7c5..72d8d3d 100644
--- a/content/content_unittests.isolate
+++ b/content/content_unittests.isolate
@@ -114,5 +114,6 @@
   ],
   'includes': [
     '../base/base.isolate',
+    '../gin/v8.isolate',
   ],
 }
diff --git a/content/public/common/content_descriptors.h b/content/public/common/content_descriptors.h
index 5a6b234..db97201 100644
--- a/content/public/common/content_descriptors.h
+++ b/content/public/common/content_descriptors.h
@@ -16,6 +16,12 @@ enum {
 #if defined(OS_ANDROID)
   kAndroidPropertyDescriptor,
   kAndroidICUDataDescriptor,
+
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA
+  kV8NativesDataDescriptor,
+  kV8SnapshotDataDescriptor,
+#endif
+
 #endif
 
   // The first key that embedders can use to register descriptors (see
diff --git a/content/public/test/DEPS b/content/public/test/DEPS
index 9c458aa..43a7d3c 100644
--- a/content/public/test/DEPS
+++ b/content/public/test/DEPS
@@ -9,6 +9,7 @@ specific_include_rules = {
   ".*\.cc": [
     # Testing utilities can access anything in content/
     "+content",
+    "+gin/public/isolate_holder.h",
     "+media/base",
     "+third_party/iaccessible2",
     "+ui/base/resource/resource_bundle.h",
diff --git a/content/public/test/content_test_suite_base.cc b/content/public/test/content_test_suite_base.cc
index 70666e5..9b11678 100644
--- a/content/public/test/content_test_suite_base.cc
+++ b/content/public/test/content_test_suite_base.cc
@@ -37,6 +37,10 @@
 #include "ui/shell_dialogs/android/shell_dialogs_jni_registrar.h"
 #endif
 
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA
+#include "gin/public/isolate_holder.h"
+#endif
+
 namespace content {
 
 class ContentTestSuiteBaseListener : public testing::EmptyTestEventListener {
@@ -62,6 +66,10 @@ void ContentTestSuiteBase::Initialize() {
   // by tests.
   base::StatisticsRecorder::Initialize();
 
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA
+  gin::IsolateHolder::LoadV8Snapshot();
+#endif
+
 #if defined(OS_ANDROID)
   // Register JNI bindings for android.
   JNIEnv* env = base::android::AttachCurrentThread();
diff --git a/content/shell/android/browsertests_apk/src/org/chromium/content_browsertests_apk/ContentBrowserTestsApplication.java b/content/shell/android/browsertests_apk/src/org/chromium/content_browsertests_apk/ContentBrowserTestsApplication.java
index 0efb5b2..1343101 100644
--- a/content/shell/android/browsertests_apk/src/org/chromium/content_browsertests_apk/ContentBrowserTestsApplication.java
+++ b/content/shell/android/browsertests_apk/src/org/chromium/content_browsertests_apk/ContentBrowserTestsApplication.java
@@ -16,7 +16,9 @@ public class ContentBrowserTestsApplication extends Application {
 
     private static final String[] MANDATORY_PAK_FILES = new String[] {
         "content_shell.pak",
-        "icudtl.dat"
+        "icudtl.dat",
+        "natives_blob.bin",
+        "snapshot_blob.bin"
     };
     private static final String PRIVATE_DATA_DIRECTORY_SUFFIX = "content_shell";
 
diff --git a/content/shell/android/linker_test_apk/src/org/chromium/chromium_linker_test_apk/ChromiumLinkerTestApplication.java b/content/shell/android/linker_test_apk/src/org/chromium/chromium_linker_test_apk/ChromiumLinkerTestApplication.java
index d996fa7..cf72619 100644
--- a/content/shell/android/linker_test_apk/src/org/chromium/chromium_linker_test_apk/ChromiumLinkerTestApplication.java
+++ b/content/shell/android/linker_test_apk/src/org/chromium/chromium_linker_test_apk/ChromiumLinkerTestApplication.java
@@ -19,10 +19,16 @@ public class ChromiumLinkerTestApplication extends Application {
      * operation. We use to link it statically to our binary, but not any more
      * so that we have to install it along with other mandatory pak files.
      * See src/third_party/icu/README.chromium.
+     *
+     *  V8's initial snapshot used to be statically linked to the binary, but
+     *  now it's loaded from external files. Therefore we need to install such
+     *  snapshots (natives_blob.bin and snapshot.bin) along with pak files.
      */
     private static final String[] MANDATORY_PAK_FILES = new String[] {
         "content_shell.pak",
-        "icudtl.dat"
+        "icudtl.dat",
+        "natives_blob.bin",
+        "snapshot_blob.bin"
     };
     private static final String PRIVATE_DATA_DIRECTORY_SUFFIX = "chromium_linker_test";
 
diff --git a/content/shell/android/shell_apk/src/org/chromium/content_shell_apk/ContentShellApplication.java b/content/shell/android/shell_apk/src/org/chromium/content_shell_apk/ContentShellApplication.java
index c430baf..5053e32 100644
--- a/content/shell/android/shell_apk/src/org/chromium/content_shell_apk/ContentShellApplication.java
+++ b/content/shell/android/shell_apk/src/org/chromium/content_shell_apk/ContentShellApplication.java
@@ -22,10 +22,16 @@ public class ContentShellApplication extends ContentApplication {
      * operation. We use to link it statically to our binary, but not any more
      * so that we have to install it along with other mandatory pak files.
      * See src/third_party/icu/README.chromium.
+     *
+     *  V8's initial snapshot used to be statically linked to the binary, but
+     *  now it's loaded from external files. Therefore we need to install such
+     *  snapshots (natives_blob.bin and snapshot.bin) along with pak files.
      */
     private static final String[] MANDATORY_PAK_FILES = new String[] {
         "content_shell.pak",
-        "icudtl.dat"
+        "icudtl.dat",
+        "natives_blob.bin",
+        "snapshot_blob.bin"
     };
     private static final String PRIVATE_DATA_DIRECTORY_SUFFIX = "content_shell";
 
diff --git a/content/test/DEPS b/content/test/DEPS
index 4a3e002..7d1b3d9 100644
--- a/content/test/DEPS
+++ b/content/test/DEPS
@@ -3,6 +3,8 @@ include_rules = [
   "+chromeos/audio", # For WebRTC tests.
   # Testing utilities can access anything in content/
   "+content",
+  # For loading V8's initial snapshot from external files.
+  "+gin/public/isolate_holder.h",
   "+media/audio", # For AudioParameters in WebRTC tests.
   "+media/base",  # For ChannelLayout in WebRTC tests.
   "+ui/base/resource/data_pack.h",
diff --git a/content/test/content_test_launcher.cc b/content/test/content_test_launcher.cc
index e19db37..82466e7 100644
--- a/content/test/content_test_launcher.cc
+++ b/content/test/content_test_launcher.cc
@@ -21,6 +21,10 @@
 #include "media/base/media_switches.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA
+#include "gin/public/isolate_holder.h"
+#endif
+
 #if defined(OS_ANDROID)
 #include "base/message_loop/message_loop.h"
 #include "content/app/mojo/mojo_init.h"
@@ -53,6 +57,10 @@ class ContentBrowserTestSuite : public ContentTestSuiteBase {
     base::i18n::AllowMultipleInitializeCallsForTesting();
     base::i18n::InitializeICU();
 
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA
+    gin::IsolateHolder::LoadV8Snapshot();
+#endif
+
     // This needs to be done before base::TestSuite::Initialize() is called,
     // as it also tries to set MessagePumpForUIFactory.
     if (!base::MessageLoop::InitMessagePumpForUIFactory(
diff --git a/content/test/test_blink_web_unit_test_support.cc b/content/test/test_blink_web_unit_test_support.cc
index 8f743ed..0fed5ab 100644
--- a/content/test/test_blink_web_unit_test_support.cc
+++ b/content/test/test_blink_web_unit_test_support.cc
@@ -38,6 +38,10 @@
 #include "base/mac/scoped_nsautorelease_pool.h"
 #endif
 
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA
+#include "gin/public/isolate_holder.h"
+#endif
+
 namespace content {
 
 TestBlinkWebUnitTestSupport::TestBlinkWebUnitTestSupport() {
@@ -54,6 +58,10 @@ TestBlinkWebUnitTestSupport::TestBlinkWebUnitTestSupport() {
       new base::StatsTable(base::StatsTable::TableIdentifier(), 20, 200));
   base::StatsTable::set_current(stats_table_.get());
 
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA
+  gin::IsolateHolder::LoadV8Snapshot();
+#endif
+
   blink::initialize(this);
   blink::mainThreadIsolate()->SetCounterFunction(
       base::StatsTable::FindLocation);
diff --git a/gin/isolate_holder.cc b/gin/isolate_holder.cc
index 740e136..334c0e0 100644
--- a/gin/isolate_holder.cc
+++ b/gin/isolate_holder.cc
@@ -18,6 +18,11 @@
 #include "gin/public/v8_platform.h"
 #include "gin/run_microtasks_observer.h"
 
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA
+#include "base/files/memory_mapped_file.h"
+#include "base/path_service.h"
+#endif  // V8_USE_EXTERNAL_STARTUP_DATA
+
 namespace gin {
 
 namespace {
@@ -29,8 +34,70 @@ bool GenerateEntropy(unsigned char* buffer, size_t amount) {
   return true;
 }
 
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA
+base::MemoryMappedFile* g_mapped_natives = NULL;
+base::MemoryMappedFile* g_mapped_snapshot = NULL;
+
+bool MapV8Files(base::FilePath* natives_path, base::FilePath* snapshot_path,
+                int natives_fd = -1, int snapshot_fd = -1) {
+  int flags = base::File::FLAG_OPEN | base::File::FLAG_READ;
+
+  g_mapped_natives = new base::MemoryMappedFile;
+  if (!g_mapped_natives->IsValid()) {
+    if (natives_fd == -1
+        ? !g_mapped_natives->Initialize(base::File(*natives_path, flags))
+        : !g_mapped_natives->Initialize(base::File(natives_fd))) {
+      delete g_mapped_natives;
+      g_mapped_natives = NULL;
+      LOG(FATAL) << "Couldn't mmap v8 natives data file";
+      return false;
+    }
+  }
+
+  g_mapped_snapshot = new base::MemoryMappedFile;
+  if (!g_mapped_snapshot->IsValid()) {
+    if (snapshot_fd == -1
+        ? !g_mapped_snapshot->Initialize(base::File(*snapshot_path, flags))
+        : !g_mapped_snapshot->Initialize(base::File(snapshot_fd))) {
+      delete g_mapped_snapshot;
+      g_mapped_snapshot = NULL;
+      LOG(ERROR) << "Couldn't mmap v8 snapshot data file";
+      return false;
+    }
+  }
+
+  return true;
+}
+#endif  // V8_USE_EXTERNAL_STARTUP_DATA
+
 }  // namespace
 
+
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA
+// static
+bool IsolateHolder::LoadV8Snapshot() {
+  if (g_mapped_natives && g_mapped_snapshot)
+    return true;
+
+  base::FilePath data_path;
+  PathService::Get(base::DIR_ANDROID_APP_DATA, &data_path);
+  DCHECK(!data_path.empty());
+
+  base::FilePath natives_path = data_path.AppendASCII("natives_blob.bin");
+  base::FilePath snapshot_path = data_path.AppendASCII("snapshot_blob.bin");
+
+  return MapV8Files(&natives_path, &snapshot_path);
+}
+
+//static
+bool IsolateHolder::LoadV8SnapshotFD(int natives_fd, int snapshot_fd) {
+  if (g_mapped_natives && g_mapped_snapshot)
+    return true;
+
+  return MapV8Files(NULL, NULL, natives_fd, snapshot_fd);
+}
+#endif  // V8_USE_EXTERNAL_STARTUP_DATA
+
 IsolateHolder::IsolateHolder() {
   CHECK(g_array_buffer_allocator)
       << "You need to invoke gin::IsolateHolder::Initialize first";
@@ -88,6 +155,19 @@ void IsolateHolder::Initialize(ScriptMode mode,
     v8::V8::SetFlagsFromString(v8_flags, sizeof(v8_flags) - 1);
   }
   v8::V8::SetEntropySource(&GenerateEntropy);
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA
+  v8::StartupData natives;
+  natives.data = reinterpret_cast<const char*>(g_mapped_natives->data());
+  natives.raw_size = g_mapped_natives->length();
+  natives.compressed_size = g_mapped_natives->length();
+  v8::V8::SetNativesDataBlob(&natives);
+
+  v8::StartupData snapshot;
+  snapshot.data = reinterpret_cast<const char*>(g_mapped_snapshot->data());
+  snapshot.raw_size = g_mapped_snapshot->length();
+  snapshot.compressed_size = g_mapped_snapshot->length();
+  v8::V8::SetSnapshotDataBlob(&snapshot);
+#endif  // V8_USE_EXTERNAL_STARTUP_DATA
   v8::V8::Initialize();
   v8_is_initialized = true;
 }
diff --git a/gin/public/isolate_holder.h b/gin/public/isolate_holder.h
index 29cc208..4e14ade 100644
--- a/gin/public/isolate_holder.h
+++ b/gin/public/isolate_holder.h
@@ -31,7 +31,9 @@ class GIN_EXPORT IsolateHolder {
   ~IsolateHolder();
 
   // Should be invoked once before creating IsolateHolder instances to
-  // initialize V8 and Gin.
+  // initialize V8 and Gin. In case V8_USE_EXTERNAL_STARTUP_DATA is defined,
+  // V8's initial snapshot should be loaded (by calling LoadV8Snapshot or
+  // LoadV8SnapshotFD) before calling Initialize.
   static void Initialize(ScriptMode mode,
                          v8::ArrayBuffer::Allocator* allocator);
 
@@ -49,6 +51,13 @@ class GIN_EXPORT IsolateHolder {
   // thread.
   void RemoveRunMicrotasksObserver();
 
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA
+#ifdef OS_ANDROID
+  static bool LoadV8SnapshotFD(int natives_fd, int snapshot_fd);
+#endif
+  static bool LoadV8Snapshot();
+#endif  // V8_USE_EXTERNAL_STARTUP_DATA
+
  private:
   v8::Isolate* isolate_;
   scoped_ptr<PerIsolateData> isolate_data_;
diff --git a/gin/shell/gin_main.cc b/gin/shell/gin_main.cc
index b17ec0a..2f7998e 100644
--- a/gin/shell/gin_main.cc
+++ b/gin/shell/gin_main.cc
@@ -60,6 +60,9 @@ int main(int argc, char** argv) {
   base::AtExitManager at_exit;
   CommandLine::Init(argc, argv);
   base::i18n::InitializeICU();
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA
+  gin::IsolateHolder::LoadV8Snapshot();
+#endif
 
   gin::IsolateHolder::Initialize(gin::IsolateHolder::kStrictMode,
                                  gin::ArrayBufferAllocator::SharedInstance());
diff --git a/gin/shell_runner_unittest.cc b/gin/shell_runner_unittest.cc
index 07ab678..7134de1 100644
--- a/gin/shell_runner_unittest.cc
+++ b/gin/shell_runner_unittest.cc
@@ -10,6 +10,10 @@
 #include "gin/public/isolate_holder.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA
+#include "gin/public/isolate_holder.h"
+#endif
+
 using v8::Isolate;
 using v8::Object;
 using v8::Script;
@@ -20,6 +24,10 @@ namespace gin {
 TEST(RunnerTest, Run) {
   std::string source = "this.result = 'PASS';\n";
 
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA
+  gin::IsolateHolder::LoadV8Snapshot();
+#endif
+
   gin::IsolateHolder::Initialize(gin::IsolateHolder::kStrictMode,
                                  gin::ArrayBufferAllocator::SharedInstance());
   gin::IsolateHolder instance;
diff --git a/gin/test/file_runner.cc b/gin/test/file_runner.cc
index 83228d6..b639d06 100644
--- a/gin/test/file_runner.cc
+++ b/gin/test/file_runner.cc
@@ -19,6 +19,10 @@
 #include "gin/try_catch.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA
+#include "gin/public/isolate_holder.h"
+#endif
+
 namespace gin {
 
 namespace {
@@ -58,6 +62,10 @@ void RunTestFromFile(const base::FilePath& path, FileRunnerDelegate* delegate,
 
   base::MessageLoop message_loop;
 
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA
+  gin::IsolateHolder::LoadV8Snapshot();
+#endif
+
   gin::IsolateHolder::Initialize(gin::IsolateHolder::kStrictMode,
                                  gin::ArrayBufferAllocator::SharedInstance());
   gin::IsolateHolder instance;
diff --git a/gin/test/v8_test.cc b/gin/test/v8_test.cc
index cb6d573..a022511 100644
--- a/gin/test/v8_test.cc
+++ b/gin/test/v8_test.cc
@@ -7,6 +7,10 @@
 #include "gin/array_buffer.h"
 #include "gin/public/isolate_holder.h"
 
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA
+#include "gin/public/isolate_holder.h"
+#endif
+
 using v8::Context;
 using v8::Local;
 using v8::HandleScope;
@@ -20,6 +24,9 @@ V8Test::~V8Test() {
 }
 
 void V8Test::SetUp() {
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA
+  gin::IsolateHolder::LoadV8Snapshot();
+#endif
   gin::IsolateHolder::Initialize(gin::IsolateHolder::kStrictMode,
                                  gin::ArrayBufferAllocator::SharedInstance());
   instance_.reset(new gin::IsolateHolder);
diff --git a/gin/v8.isolate b/gin/v8.isolate
new file mode 100644
index 0000000..14d8a2c
--- /dev/null
+++ b/gin/v8.isolate
@@ -0,0 +1,15 @@
+# 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.
+{
+  'conditions': [
+    ['v8_use_external_startup_data==1', {
+      'variables': {
+        'isolate_dependency_tracked': [
+          '<(PRODUCT_DIR)/natives_blob.bin',
+          '<(PRODUCT_DIR)/snapshot_blob.bin',
+        ],
+      },
+    }],
+  ],
+}
diff --git a/net/net.gyp b/net/net.gyp
index e570e8e..f762ad6 100644
--- a/net/net.gyp
+++ b/net/net.gyp
@@ -789,6 +789,11 @@
             ],
           },
         ],
+        ['v8_use_external_startup_data==1', {
+          'dependencies': [
+            '../gin/gin.gyp:gin',
+          ]
+        }],
       ],
       'target_conditions': [
         # These source files are excluded by default platform rules, but they
@@ -1651,6 +1656,23 @@
           ],
           'variables': {
             'test_suite_name': 'net_unittests',
+            'conditions': [
+              ['v8_use_external_startup_data==1', {
+                'additional_input_paths': [
+                  '<(PRODUCT_DIR)/natives_blob.bin',
+                  '<(PRODUCT_DIR)/snapshot_blob.bin',
+                ],
+                'copies': [
+                  {
+                  'destination': '<(PRODUCT_DIR)/net_unittests_apk/assets',
+                    'files': [
+                      '<(PRODUCT_DIR)/natives_blob.bin',
+                      '<(PRODUCT_DIR)/snapshot_blob.bin',
+                    ],
+                  },
+                ],
+              }],
+            ],
           },
           'includes': [ '../build/apk_test.gypi' ],
         },
diff --git a/net/net.isolate b/net/net.isolate
index f5ca9b5..cd2d266 100644
--- a/net/net.isolate
+++ b/net/net.isolate
@@ -6,5 +6,6 @@
   ],
   'includes': [
     '../base/base.isolate',
+    '../gin/v8.isolate',
   ],
 }
diff --git a/net/net_unittests.isolate b/net/net_unittests.isolate
index 15b3f08..e57f957 100644
--- a/net/net_unittests.isolate
+++ b/net/net_unittests.isolate
@@ -42,5 +42,6 @@
   ],
   'includes': [
     '../base/base.isolate',
+    '../gin/v8.isolate',
   ],
 }
diff --git a/net/test/run_all_unittests.cc b/net/test/run_all_unittests.cc
index a035057..12df717 100644
--- a/net/test/run_all_unittests.cc
+++ b/net/test/run_all_unittests.cc
@@ -23,6 +23,10 @@
 #include "net/proxy/proxy_resolver_v8.h"
 #endif
 
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA
+#include "gin/public/isolate_holder.h"
+#endif
+
 using net::internal::ClientSocketPoolBaseHelper;
 using net::SpdySession;
 
@@ -57,6 +61,10 @@ int main(int argc, char** argv) {
   // single-threaded.
   net::EnableSSLServerSockets();
 
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA
+  gin::IsolateHolder::LoadV8Snapshot();
+#endif
+
 #if !defined(OS_IOS)
   net::ProxyResolverV8::EnsureIsolateCreated();
 #endif
diff --git a/testing/android/java/src/org/chromium/native_test/ChromeNativeTestActivity.java b/testing/android/java/src/org/chromium/native_test/ChromeNativeTestActivity.java
index 9b241d1..f5d381a 100644
--- a/testing/android/java/src/org/chromium/native_test/ChromeNativeTestActivity.java
+++ b/testing/android/java/src/org/chromium/native_test/ChromeNativeTestActivity.java
@@ -36,7 +36,7 @@ public class ChromeNativeTestActivity extends Activity {
         PathUtils.setPrivateDataDirectorySuffix("chrome");
 
         ResourceExtractor resourceExtractor = ResourceExtractor.get(getApplicationContext());
-        resourceExtractor.setExtractAllPaksForTesting();
+        resourceExtractor.setExtractAllPaksAndV8SnapshotForTesting();
         resourceExtractor.startExtractingResources();
         resourceExtractor.waitForCompletion();
 
diff --git a/third_party/android_webview_glue/android_webview_glue.gypi b/third_party/android_webview_glue/android_webview_glue.gypi
index 3ba317a..098a6fd 100644
--- a/third_party/android_webview_glue/android_webview_glue.gypi
+++ b/third_party/android_webview_glue/android_webview_glue.gypi
@@ -19,6 +19,12 @@
                 '<(PRODUCT_DIR)/icudtl.dat',
               ],
             }],
+            ['v8_use_external_startup_data==1', {
+              'files': [
+                '<(PRODUCT_DIR)/natives_blob.bin',
+                '<(PRODUCT_DIR)/snapshot_blob.bin',
+              ],
+            }],
           ],
         },
       ],
diff --git a/third_party/android_webview_glue/android_webview_glue_common.gypi b/third_party/android_webview_glue/android_webview_glue_common.gypi
index 896dee4..2b818e2 100644
--- a/third_party/android_webview_glue/android_webview_glue_common.gypi
+++ b/third_party/android_webview_glue/android_webview_glue_common.gypi
@@ -31,6 +31,12 @@
           '<(PRODUCT_DIR)/icudtl.dat',
         ],
       }],
+      ['v8_use_external_startup_data==1', {
+        'additional_input_paths': [
+          '<(PRODUCT_DIR)/natives_blob.bin',
+          '<(PRODUCT_DIR)/snapshot_blob.bin',
+        ],
+      }],
     ],
   },
   'includes': [ '../../build/java_apk.gypi' ],
diff --git a/tools/gypv8sh.py b/tools/gypv8sh.py
index 3f81a8b..9724ed4 100755
--- a/tools/gypv8sh.py
+++ b/tools/gypv8sh.py
@@ -26,6 +26,8 @@ def main ():
   parser.add_option('--deps_js', action="store",
                     help=("Path to deps.js for dependency resolution, " +
                           "optional."))
+  parser.add_option('--external', action='store',
+                    help="Load V8's initial snapshot from external files (y/n)")
   (opts, args) = parser.parse_args()
 
   if len(args) != 9:
@@ -36,6 +38,12 @@ def main ():
   icudatafile = os.path.join(os.path.dirname(v8_shell), 'icudtl.dat')
   if os.path.exists(icudatafile):
     cmd.extend(['--icu-data-file=%s' % icudatafile])
+  v8nativesfile = os.path.join(os.path.dirname(v8_shell), 'natives_blob.bin')
+  if opts.external == 'y' and os.path.exists(v8nativesfile):
+    cmd.extend(['--natives_blob=%s' % v8nativesfile])
+  v8snapshotfile = os.path.join(os.path.dirname(v8_shell), 'snapshot_blob.bin')
+  if opts.external == 'y' and os.path.exists(v8snapshotfile):
+    cmd.extend(['--snapshot_blob=%s' % v8snapshotfile])
   arguments = [js2webui, inputfile, inputrelfile, opts.deps_js,
                cxxoutfile, test_type]
   cmd.extend(['-e', "arguments=" + json.dumps(arguments), mock_js,