devtools: Adds Page.getLayoutMetrics.

third_party/WebKit/Source/core/inspector/InspectorPageAgent.h

Index: third_party/WebKit/Source/core/inspector/InspectorPageAgent.h
diff --git a/third_party/WebKit/Source/core/inspector/InspectorPageAgent.h b/third_party/WebKit/Source/core/inspector/InspectorPageAgent.h
index 99c77e635ea23f71d1df154f3371eaac09c94d0c..d437084d10e2b224b5aa5c02596e68528d03092b 100644
--- a/third_party/WebKit/Source/core/inspector/InspectorPageAgent.h
+++ b/third_party/WebKit/Source/core/inspector/InspectorPageAgent.h
@@ -144,6 +144,10 @@ class CORE_EXPORT InspectorPageAgent final
                         const Maybe<String>& message) override;
   void setBlockedEventsWarningThreshold(ErrorString*,
                                         double threshold) override;
+  void getLayoutMetrics(
+      ErrorString*,
+      std::unique_ptr<protocol::Page::LayoutViewport>*,
+      std::unique_ptr<protocol::Page::VisualViewport>*) override;
 
   // InspectorInstrumentation API
   void didClearDocumentOfWindowObject(LocalFrame*);