Remove Object.observe UseCounter and deprecation warning

third_party/WebKit/Source/bindings/core/v8/V8PerIsolateData.cpp

Index: third_party/WebKit/Source/bindings/core/v8/V8PerIsolateData.cpp
diff --git a/third_party/WebKit/Source/bindings/core/v8/V8PerIsolateData.cpp b/third_party/WebKit/Source/bindings/core/v8/V8PerIsolateData.cpp
index baeb5c30ad90c60200dc696907d9b99f4eb32e41..b157d8ba4384614cff85b6e7adbf907505359096 100644
--- a/third_party/WebKit/Source/bindings/core/v8/V8PerIsolateData.cpp
+++ b/third_party/WebKit/Source/bindings/core/v8/V8PerIsolateData.cpp
@@ -113,10 +113,6 @@ void V8PerIsolateData::useCounterCallback(v8::Isolate* isolate, v8::Isolate::Use
     case v8::Isolate::kLegacyConst:
         blinkFeature = UseCounter::LegacyConst;
         break;
-    case v8::Isolate::kObjectObserve:
-        blinkFeature = UseCounter::ObjectObserve;
-        deprecated = true;
-        break;
     case v8::Isolate::kSloppyMode:
         blinkFeature = UseCounter::V8SloppyMode;
         break;