Reimplement canvas using view classes (#80)

Replaces Brian's original procedural code with view classes. The views are rudimentary implementations of iOS UIKit-style UIViews.

src/App.js

@@ -1,12 +1,10 @@
 // @flow
 
-import type {FlamechartData, ReactLane, ReactProfilerData} from './types';
+import type {FlamechartData, ReactProfilerData} from './types';
 
 import React, {useState, useCallback} from 'react';
 import {unstable_batchedUpdates} from 'react-dom';
 
-import {getLaneHeight} from './canvas/canvasUtils';
-import {REACT_TOTAL_NUM_LANES} from './constants';
 import ImportPage from './ImportPage';
 import CanvasPage from './CanvasPage';
 
@@ -15,7 +13,6 @@ export default function App() {
     null,
   );
   const [flamechart, setFlamechart] = useState<FlamechartData | null>(null);
-  const [schedulerCanvasHeight, setSchedulerCanvasHeight] = useState<number>(0);
 
   const handleDataImported = useCallback(
     (
@@ -25,27 +22,11 @@ export default function App() {
       unstable_batchedUpdates(() => {
         setProfilerData(importedProfilerData);
         setFlamechart(importedFlamechart);
-
-        const lanesToRender: ReactLane[] = Array.from(
-          Array(REACT_TOTAL_NUM_LANES).keys(),
-        );
-        // TODO: Figure out if this is necessary
-        setSchedulerCanvasHeight(
-          lanesToRender.reduce((height, lane) => {
-            return height + getLaneHeight(importedProfilerData, lane);
-          }, 0),
-        );
       });
     },
   );
   if (profilerData && flamechart) {
-    return (
-      <CanvasPage
-        profilerData={profilerData}
-        flamechart={flamechart}
-        schedulerCanvasHeight={schedulerCanvasHeight}
-      />
-    );
+    return <CanvasPage profilerData={profilerData} flamechart={flamechart} />;
   } else {
     return <ImportPage onDataImported={handleDataImported} />;
   }