Name V8 snapshot according to target architecture (32/64 bit).

android_webview/lib/main/aw_main_delegate.cc

Index: android_webview/lib/main/aw_main_delegate.cc
diff --git a/android_webview/lib/main/aw_main_delegate.cc b/android_webview/lib/main/aw_main_delegate.cc
index 8ad76578ffb1c0075fea0c22ae30e09e34dbd058..b89ee116d96bacdf8d522d0c55caa169c525dc88 100644
--- a/android_webview/lib/main/aw_main_delegate.cc
+++ b/android_webview/lib/main/aw_main_delegate.cc
@@ -92,10 +92,20 @@ bool AwMainDelegate::BasicStartupComplete(int* exit_code) {
   // In multi-process mode this code would live in
   // AwContentBrowserClient::GetAdditionalMappedFilesForChildProcess.
 #ifdef V8_USE_EXTERNAL_STARTUP_DATA
+#ifdef __LP64__
+  const char kNativesFileName[] = "natives_blob_64.bin";
+  const char kSnapshotFileName[] = "snapshot_blob_64.bin";
+#else
+  const char kNativesFileName[] = "natives_blob_32.bin";
+  const char kSnapshotFileName[] = "snapshot_blob_32.bin";
+#endif // __LP64__
+  // TODO(gsennton) we should use
+  // gin::IsolateHolder::kNativesFileName/kSnapshotFileName
+  // here when those files have arch specific names http://crbug.com/455699
   CHECK(AwAssets::RegisterAssetWithGlobalDescriptors(
-      kV8NativesDataDescriptor, gin::IsolateHolder::kNativesFileName));
+      kV8NativesDataDescriptor, kNativesFileName));
   CHECK(AwAssets::RegisterAssetWithGlobalDescriptors(
-      kV8SnapshotDataDescriptor, gin::IsolateHolder::kSnapshotFileName));
+      kV8SnapshotDataDescriptor, kSnapshotFileName));
 #endif
   // TODO(mkosiba): make this CHECK when the android_webview_build uses an asset
   // from the .apk too.