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 b82367750bf38ac1b4c91d199303da32b89a27a2..89f0012d498ac8491f5e2d9ead3beda72a667ae0 100644
--- a/content/renderer/renderer_blink_platform_impl.cc
+++ b/content/renderer/renderer_blink_platform_impl.cc
@@ -47,6 +47,7 @@
 #include "content/common/gpu/gpu_process_launch_causes.h"
 #include "content/common/mime_registry_messages.h"
 #include "content/common/render_process_messages.h"
+#include "content/public/child/url_conversion.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/common/service_registry.h"
 #include "content/public/common/webplugininfo.h"
@@ -1025,7 +1026,7 @@ RendererBlinkPlatformImpl::createOffscreenGraphicsContext3D(
           gpu_channel_host.get(),
           attributes,
           lose_context_when_out_of_memory,
-          GURL(attributes.topDocumentURL),
+          WebStringToGURL(attributes.topDocumentURL),
           limits,
           static_cast<WebGraphicsContext3DCommandBufferImpl*>(share_context)));