[Bindings] Create and use V8 context snapshots

third_party/WebKit/Source/bindings/core/v8/V8Initializer.cpp

Index: third_party/WebKit/Source/bindings/core/v8/V8Initializer.cpp
diff --git a/third_party/WebKit/Source/bindings/core/v8/V8Initializer.cpp b/third_party/WebKit/Source/bindings/core/v8/V8Initializer.cpp
index e73d307014aae0c4384580b9ff7a099ef35e8710..f5a6bd4fe72692d5c9cfd347326a8a58afb1fb5c 100644
--- a/third_party/WebKit/Source/bindings/core/v8/V8Initializer.cpp
+++ b/third_party/WebKit/Source/bindings/core/v8/V8Initializer.cpp
@@ -40,6 +40,7 @@
 #include "bindings/core/v8/V8ErrorHandler.h"
 #include "bindings/core/v8/V8GCController.h"
 #include "bindings/core/v8/V8IdleTaskRunner.h"
+#include "bindings/core/v8/V8SnapshotUtil.h"
 #include "bindings/core/v8/WorkerOrWorkletScriptController.h"
 #include "core/dom/Document.h"
 #include "core/dom/ExecutionContext.h"
@@ -388,6 +389,9 @@ static void InitializeV8Common(v8::Isolate* isolate) {
   isolate->SetUseCounterCallback(&UseCounterCallback);
   isolate->SetWasmModuleCallback(WasmModuleOverride);
   isolate->SetWasmInstanceCallback(WasmInstanceOverride);
+
+  v8::HandleScope handle_scope(isolate);
+  V8SnapshotUtil::EnsureInterfaceTemplates(isolate);
 }
 
 namespace {
@@ -442,14 +446,21 @@ void V8Initializer::InitializeMainThread() {
                                  v8_extras_mode, &array_buffer_allocator);
 
   // NOTE: Some threads (namely utility threads) don't have a scheduler.
-  WebScheduler* scheduler = Platform::Current()->CurrentThread()->Scheduler();
+  Platform* platform = Platform::Current();
+  WebThread* thread = platform->CurrentThread();

[Yuki, 2017/06/23 15:20:44]

As I took a look at the codebase, it seems better to implement
Platform::CurrentThread() so that it returns a non-null WebThread with no
implementation.

For example,
https://cs.chromium.org/chromium/src/third_party/WebKit/Source/platform/testi...
https://cs.chromium.org/chromium/src/third_party/WebKit/Source/core/dom/IdleD...
https://cs.chromium.org/chromium/src/third_party/WebKit/Source/core/dom/Scrip...

There are many call sites of CurrentThread() and the contract seems that it
never returns null.  Then, we shouldn't change that contract.

[peria, 2017/06/27 09:52:37]

Done.

+  WebScheduler* scheduler = thread ? thread->Scheduler() : nullptr;
+
   // When timer task runner is used for PerIsolateData, GC tasks are getting
   // throttled and memory usage goes up. For now we're using loading task queue
   // to prevent this.
   // TODO(altimin): Consider switching to timerTaskRunner here.
   v8::Isolate* isolate = V8PerIsolateData::Initialize(
       scheduler ? scheduler->LoadingTaskRunner()
-                : Platform::Current()->CurrentThread()->GetWebTaskRunner());
+                : thread ? thread->GetWebTaskRunner() : nullptr,

[Yuki, 2017/06/23 15:20:44]

Ditto.

[peria, 2017/06/27 09:52:37]

Done.

+      V8SnapshotUtil::GetReferenceTable(),
+      platform->IsToTakeV8Snapshot()
+          ? V8PerIsolateData::V8ContextMode::kTakeSnapshot
+          : V8PerIsolateData::V8ContextMode::kUseSnapshot);
 
   InitializeV8Common(isolate);