[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 f48e04e15a46b505d498fdcdf93b76e698860b29..f65e2123b5f47c3e55e25f07d00cb6ca63d3e606 100644
--- a/third_party/WebKit/Source/bindings/core/v8/V8Initializer.cpp
+++ b/third_party/WebKit/Source/bindings/core/v8/V8Initializer.cpp
@@ -41,6 +41,7 @@
 #include "bindings/core/v8/V8GCController.h"
 #include "bindings/core/v8/V8IdleTaskRunner.h"
 #include "bindings/core/v8/V8Location.h"
+#include "bindings/core/v8/V8SnapshotCreator.h"
 #include "bindings/core/v8/V8Window.h"
 #include "bindings/core/v8/WorkerOrWorkletScriptController.h"
 #include "core/dom/Document.h"
@@ -446,7 +447,7 @@ static void AdjustAmountOfExternalAllocatedMemory(int64_t diff) {
   v8::Isolate::GetCurrent()->AdjustAmountOfExternalAllocatedMemory(diff);
 }
 
-void V8Initializer::InitializeMainThread() {
+void V8Initializer::InitializeMainThread(intptr_t* table) {

[Yuki, 2017/05/12 15:20:10]

|table| doesn't make much sense.
v8_snapshot_external_references for example?

Should this be retrieved through V8SnapshotCreator::GetExternalReferences()
rather than passing in as an argument?

[peria, 2017/05/30 08:25:42]

Acknowledged.

   DCHECK(IsMainThread());
 
   WTF::ArrayBufferContents::Initialize(AdjustAmountOfExternalAllocatedMemory);
@@ -459,14 +460,17 @@ 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();
+  WebThread* thread = Platform::Current()->CurrentThread();
+  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,
+      table, V8SnapshotCreator::TakingSnapshot());
 
   InitializeV8Common(isolate);