[Fiber] Updates from inside componentDidMount/Update should have Task priority

scripts/fiber/tests-failing.txt

@@ -72,6 +72,9 @@ src/renderers/art/__tests__/ReactART-test.js
 * resolves refs before componentDidMount
 * resolves refs before componentDidUpdate
 
+src/renderers/dom/__tests__/ReactDOMProduction-test.js
+* should throw with an error code in production
+
 src/renderers/dom/shared/__tests__/CSSPropertyOperations-test.js
 * should set style attribute when styles exist
 * should warn when using hyphenated style names

scripts/fiber/tests-passing.txt

@@ -453,7 +453,6 @@ src/renderers/dom/__tests__/ReactDOMProduction-test.js
 * should use prod React
 * should handle a simple flow
 * should call lifecycle methods
-* should throw with an error code in production
 
 src/renderers/dom/fiber/__tests__/ReactDOMFiber-test.js
 * should render strings as children
@@ -846,18 +845,6 @@ src/renderers/shared/fiber/__tests__/ReactIncrementalScheduling-test.js
 * splits deferred work on multiple roots
 * works on deferred roots in the order they were scheduled
 * handles interleaved deferred and animation work
-* performs animation work in animation callback
-* schedules deferred work in animation callback
-* schedules deferred work and performs animation work in animation callback
-* performs animation work and schedules deferred work in animation callback
-* performs deferred work in deferred callback if it has time
-* schedules deferred work in deferred callback if it runs out of time
-* performs animated work in deferred callback if it has time
-* performs animated work and deferred work in deferred callback if it has time
-* performs deferred and animated work work in deferred callback if it has time
-* schedules animated work in deferred callback if it runs out of time
-* schedules animated work and deferred work in deferred callback if it runs out of time
-* schedules deferred work and animated work in deferred callback if it runs out of time
 
 src/renderers/shared/fiber/__tests__/ReactIncrementalSideEffects-test.js
 * can update child nodes of a host instance
@@ -878,6 +865,7 @@ src/renderers/shared/fiber/__tests__/ReactIncrementalSideEffects-test.js
 * calls setState callback even if component bails out
 * calls componentWillUnmount after a deletion, even if nested
 * calls componentDidMount/Update after insertion/update
+* schedules sync updates when inside componentDidMount/Update
 * invokes ref callbacks after insertion/update/unmount
 * supports string refs
 

src/renderers/shared/fiber/ReactFiberScheduler.js

@@ -209,7 +209,10 @@ module.exports = function<T, P, I, TI, C>(config : HostConfig<T, P, I, TI, C>) {
     while (effectfulFiber) {
       if (effectfulFiber.effectTag & (Update | Callback)) {
         const current = effectfulFiber.alternate;
+        const previousPriorityContext = priorityContext;
+        priorityContext = TaskPriority;
         commitLifeCycles(current, effectfulFiber);
+        priorityContext = previousPriorityContext;
       }
       const next = effectfulFiber.nextEffect;
       // Ensure that we clean these up so that we don't accidentally keep them.