DevTools: forward Up/Down keys to profiles sidebar from FlameChart

Source/devtools/front_end/ui_lazy/FlameChart.js

Index: Source/devtools/front_end/ui_lazy/FlameChart.js
diff --git a/Source/devtools/front_end/ui_lazy/FlameChart.js b/Source/devtools/front_end/ui_lazy/FlameChart.js
index 0a3664ccbb7c7c46f0b45bbe511785891c376167..4bd3f0c7143db037e563c1cf483fc75222417827 100644
--- a/Source/devtools/front_end/ui_lazy/FlameChart.js
+++ b/Source/devtools/front_end/ui_lazy/FlameChart.js
@@ -104,6 +104,8 @@ WebInspector.FlameChart = function(dataProvider, flameChartDelegate, isTopDown)
     this._selectedEntryIndex = -1;
     this._rawTimelineDataLength = 0;
     this._textWidth = {};
+
+    this._lastMouseOffsetX = 0;
 }
 
 WebInspector.FlameChart.DividersBarHeight = 18;