Reduce string copies in GURL creation

content/renderer/renderer_blink_platform_impl.cc

Index: content/renderer/renderer_blink_platform_impl.cc
diff --git a/content/renderer/renderer_blink_platform_impl.cc b/content/renderer/renderer_blink_platform_impl.cc
index c4d4fed540997988029806547394e24570fc1214..043e3d084f5e295e8976d0c0a1003fd1cbc403d6 100644
--- a/content/renderer/renderer_blink_platform_impl.cc
+++ b/content/renderer/renderer_blink_platform_impl.cc
@@ -81,6 +81,7 @@
 #include "media/filters/stream_parser_factory.h"
 #include "storage/common/database/database_identifier.h"
 #include "storage/common/quota/quota_types.h"
+#include "third_party/WebKit/public/platform/URLConversion.h"
 #include "third_party/WebKit/public/platform/WebBatteryStatusListener.h"
 #include "third_party/WebKit/public/platform/WebBlobRegistry.h"
 #include "third_party/WebKit/public/platform/WebDeviceLightListener.h"
@@ -1026,7 +1027,7 @@ RendererBlinkPlatformImpl::createOffscreenGraphicsContext3D(
           gpu_channel_host.get(),
           attributes,
           lose_context_when_out_of_memory,
-          GURL(attributes.topDocumentURL),
+          blink::WebStringToGURL(attributes.topDocumentURL),
           limits,
           static_cast<WebGraphicsContext3DCommandBufferImpl*>(share_context)));