bindings: Add toBoolean() to V8Binding.h

Source/bindings/core/v8/V8Binding.cpp

Index: Source/bindings/core/v8/V8Binding.cpp
diff --git a/Source/bindings/core/v8/V8Binding.cpp b/Source/bindings/core/v8/V8Binding.cpp
index b14d0b1ad59f8a69be854f6e8883bcbf9acdfd01..98801516839b96d5f65e0ae2df6f5e9eec9826dd 100644
--- a/Source/bindings/core/v8/V8Binding.cpp
+++ b/Source/bindings/core/v8/V8Binding.cpp
@@ -108,6 +108,16 @@ PassRefPtrWillBeRawPtr<NodeFilter> toNodeFilter(v8::Handle<v8::Value> callback,
     return filter.release();
 }
 
+bool toBooleanSlow(v8::Isolate* isolate, v8::Local<v8::Value> value, ExceptionState& exceptionState)
+{
+    ASSERT(!value->IsBoolean());
+    v8::TryCatch block;
+    bool result = false;
+    if (!v8Call(value->BooleanValue(isolate->GetCurrentContext()), result, block))
+        exceptionState.rethrowV8Exception(block.Exception());
+    return result;
+}
+
 const int32_t kMaxInt32 = 0x7fffffff;
 const int32_t kMinInt32 = -kMaxInt32 - 1;
 const uint32_t kMaxUInt32 = 0xffffffff;