Update V8 to r6190 as required by WebKit r75315

Change-Id: I0b2f598e4d8748df417ad350fc47a1c465ad1fef
diff --git a/include/v8.h b/include/v8.h
index 2c0f350..883bfad 100644
--- a/include/v8.h
+++ b/include/v8.h
@@ -1651,9 +1651,9 @@
    *       the backing store is preserved while V8 has a reference.
    */
   V8EXPORT void SetIndexedPropertiesToPixelData(uint8_t* data, int length);
-  bool HasIndexedPropertiesInPixelData();
-  uint8_t* GetIndexedPropertiesPixelData();
-  int GetIndexedPropertiesPixelDataLength();
+  V8EXPORT bool HasIndexedPropertiesInPixelData();
+  V8EXPORT uint8_t* GetIndexedPropertiesPixelData();
+  V8EXPORT int GetIndexedPropertiesPixelDataLength();
 
   /**
    * Set the backing store of the indexed properties to be managed by the
@@ -1666,10 +1666,10 @@
       void* data,
       ExternalArrayType array_type,
       int number_of_elements);
-  bool HasIndexedPropertiesInExternalArrayData();
-  void* GetIndexedPropertiesExternalArrayData();
-  ExternalArrayType GetIndexedPropertiesExternalArrayDataType();
-  int GetIndexedPropertiesExternalArrayDataLength();
+  V8EXPORT bool HasIndexedPropertiesInExternalArrayData();
+  V8EXPORT void* GetIndexedPropertiesExternalArrayData();
+  V8EXPORT ExternalArrayType GetIndexedPropertiesExternalArrayDataType();
+  V8EXPORT int GetIndexedPropertiesExternalArrayDataLength();
 
   V8EXPORT static Local<Object> New();
   static inline Object* Cast(Value* obj);
@@ -3076,6 +3076,18 @@
    * Returns a persistent handle to the newly allocated context. This
    * persistent handle has to be disposed when the context is no
    * longer used so the context can be garbage collected.
+   *
+   * \param extensions An optional extension configuration containing
+   * the extensions to be installed in the newly created context.
+   *
+   * \param global_template An optional object template from which the
+   * global object for the newly created context will be created.
+   *
+   * \param global_object An optional global object to be reused for
+   * the newly created context. This global object must have been
+   * created by a previous call to Context::New with the same global
+   * template. The state of the global object will be completely reset
+   * and only object identify will remain.
    */
   static Persistent<Context> New(
       ExtensionConfiguration* extensions = NULL,