diff --git a/Libraries/Core/InitializeCore.js b/Libraries/Core/InitializeCore.js
index 9efeba237055b9..6e00fe10696a3c 100644
--- a/Libraries/Core/InitializeCore.js
+++ b/Libraries/Core/InitializeCore.js
@@ -99,6 +99,9 @@ if (!global.process.env.NODE_ENV) {
 // Set up profile
 const Systrace = require('Systrace');
 Systrace.setEnabled(global.__RCTProfileIsProfiling || false);
+if (__DEV__) {
+  global.performance = Systrace.getUserTimingPolyfill();
+}
 
 // Set up console
 const ExceptionsManager = require('ExceptionsManager');
diff --git a/Libraries/Performance/RCTRenderingPerf.js b/Libraries/Performance/RCTRenderingPerf.js
index c15e742a0d2abc..5c54d3989e92d4 100644
--- a/Libraries/Performance/RCTRenderingPerf.js
+++ b/Libraries/Performance/RCTRenderingPerf.js
@@ -11,9 +11,6 @@
  */
 'use strict';
 
-var ReactDebugTool = require('ReactDebugTool');
-var ReactPerf = require('ReactPerf');
-
 var invariant = require('fbjs/lib/invariant');
 var performanceNow = require('fbjs/lib/performanceNow');
 
@@ -24,22 +21,6 @@ type perfModule = {
 
 var perfModules = [];
 var enabled = false;
-var lastRenderStartTime = 0;
-var totalRenderDuration = 0;
-
-var RCTRenderingPerfDevtool = {
-  onBeginLifeCycleTimer(debugID, timerType) {
-    if (timerType === 'render') {
-      lastRenderStartTime = performanceNow();
-    }
-  },
-  onEndLifeCycleTimer(debugID, timerType) {
-    if (timerType === 'render') {
-      var lastRenderDuration = performanceNow() - lastRenderStartTime;
-      totalRenderDuration += lastRenderDuration;
-    }
-  },
-};
 
 var RCTRenderingPerf = {
   // Once perf is enabled, it stays enabled
@@ -53,8 +34,6 @@ var RCTRenderingPerf = {
       return;
     }
 
-    ReactPerf.start();
-    ReactDebugTool.addHook(RCTRenderingPerfDevtool);
     perfModules.forEach((module) => module.start());
   },
 
@@ -63,15 +42,6 @@ var RCTRenderingPerf = {
       return;
     }
 
-    ReactPerf.stop();
-    ReactPerf.printInclusive();
-    ReactPerf.printWasted();
-    ReactDebugTool.removeHook(RCTRenderingPerfDevtool);
-
-    console.log(`Total time spent in render(): ${totalRenderDuration.toFixed(2)} ms`);
-    lastRenderStartTime = 0;
-    totalRenderDuration = 0;
-
     perfModules.forEach((module) => module.stop());
   },
 
diff --git a/Libraries/Performance/Systrace.js b/Libraries/Performance/Systrace.js
index 15bade515b165d..8db4ad99ed6895 100644
--- a/Libraries/Performance/Systrace.js
+++ b/Libraries/Performance/Systrace.js
@@ -11,6 +11,8 @@
  */
 'use strict';
 
+const invariant = require('fbjs/lib/invariant');
+
 type RelayProfiler = {
   attachProfileHandler(
     name: string,
@@ -29,52 +31,89 @@ const TRACE_TAG_JSC_CALLS = 1 << 27;
 
 let _enabled = false;
 let _asyncCookie = 0;
+const _markStack = [];
+let _markStackIndex = -1;
 
-const ReactSystraceDevtool = __DEV__ ? {
-  onBeforeMountComponent(debugID) {
-    const ReactComponentTreeHook = require('ReactGlobalSharedState').ReactComponentTreeHook;
-    const displayName = ReactComponentTreeHook.getDisplayName(debugID);
-    Systrace.beginEvent(`ReactReconciler.mountComponent(${displayName})`);
-  },
-  onMountComponent(debugID) {
-    Systrace.endEvent();
-  },
-  onBeforeUpdateComponent(debugID) {
-    const ReactComponentTreeHook = require('ReactGlobalSharedState').ReactComponentTreeHook;
-    const displayName = ReactComponentTreeHook.getDisplayName(debugID);
-    Systrace.beginEvent(`ReactReconciler.updateComponent(${displayName})`);
-  },
-  onUpdateComponent(debugID) {
-    Systrace.endEvent();
-  },
-  onBeforeUnmountComponent(debugID) {
-    const ReactComponentTreeHook = require('ReactGlobalSharedState').ReactComponentTreeHook;
-    const displayName = ReactComponentTreeHook.getDisplayName(debugID);
-    Systrace.beginEvent(`ReactReconciler.unmountComponent(${displayName})`);
+// Implements a subset of User Timing API necessary for React measurements.
+// https://developer.mozilla.org/en-US/docs/Web/API/User_Timing_API
+const REACT_MARKER = '\u269B';
+const userTimingPolyfill = {
+  mark(markName: string) {
+    if (__DEV__) {
+      if (_enabled) {
+        _markStackIndex++;
+        _markStack[_markStackIndex] = markName;
+        let systraceLabel = markName;
+        // Since perf measurements are a shared namespace in User Timing API,
+        // we prefix all React results with a React emoji.
+        if (markName[0] === REACT_MARKER) {
+          // This is coming from React.
+          // Removing component IDs keeps trace colors stable.
+          const indexOfId = markName.lastIndexOf(' (#');
+          const cutoffIndex = indexOfId !== -1 ? indexOfId : markName.length;
+          // Also cut off the emoji because it breaks Systrace
+          systraceLabel = markName.slice(2, cutoffIndex);
+        }
+        Systrace.beginEvent(systraceLabel);
+      }
+    }
   },
-  onUnmountComponent(debugID) {
-    Systrace.endEvent();
+  measure(measureName: string, startMark: ?string, endMark: ?string) {
+    if (__DEV__) {
+      if (_enabled) {
+        invariant(
+          typeof measureName === 'string' &&
+          typeof startMark === 'string' &&
+          typeof endMark === 'undefined',
+          'Only performance.measure(string, string) overload is supported.'
+        );
+        const topMark = _markStack[_markStackIndex];
+        invariant(
+          startMark === topMark,
+          'There was a mismatching performance.measure() call. ' +
+          'Expected "%s" but got "%s."',
+          topMark,
+          startMark,
+        );
+        _markStackIndex--;
+        // We can't use more descriptive measureName because Systrace doesn't
+        // let us edit labels post factum.
+        Systrace.endEvent();
+      }
+    }
   },
-  onBeginLifeCycleTimer(debugID, timerType) {
-    const ReactComponentTreeHook = require('ReactGlobalSharedState').ReactComponentTreeHook;
-    const displayName = ReactComponentTreeHook.getDisplayName(debugID);
-    Systrace.beginEvent(`${displayName}.${timerType}()`);
+  clearMarks(markName: string) {
+    if (__DEV__) {
+      if (_enabled) {
+        if (_markStackIndex === -1) {
+          return;
+        }
+        if (markName === _markStack[_markStackIndex]) {
+          // React uses this for "cancelling" started measurements.
+          // Systrace doesn't support deleting measurements, so we just stop them.
+          userTimingPolyfill.measure(markName, markName);
+        }
+      }
+    }
   },
-  onEndLifeCycleTimer(debugID, timerType) {
-    Systrace.endEvent();
+  clearMeasures() {
+    // React calls this to avoid memory leaks in browsers, but we don't keep
+    // measurements anyway.
   },
-} : null;
+};
 
 const Systrace = {
+  getUserTimingPolyfill() {
+    return userTimingPolyfill;
+  },
+
   setEnabled(enabled: boolean) {
     if (_enabled !== enabled) {
       if (__DEV__) {
         if (enabled) {
           global.nativeTraceBeginLegacy && global.nativeTraceBeginLegacy(TRACE_TAG_JSC_CALLS);
-          require('ReactDebugTool').addHook(ReactSystraceDevtool);
         } else {
           global.nativeTraceEndLegacy && global.nativeTraceEndLegacy(TRACE_TAG_JSC_CALLS);
-          require('ReactDebugTool').removeHook(ReactSystraceDevtool);
         }
       }
       _enabled = enabled;