Revert "java: Add a choreographer frame task trait"

This reverts commit f4ba6c5b.

Reason for revert:
content_shell_test_apk failing on Android CFI
Example: https://ci.chromium.org/p/chromium/builders/ci/Android%20CFI/5101
FindIt analysis: https://findit-for-me.appspot.com/waterfall/failure?url=https://build.chromium.org/p/chromium.memory/builders/Android%20CFI/builds/5101

Original change's description:
> java: Add a choreographer frame task trait
> 
> This is useful if you need to guarantee something like a layout pass has
> occurred before your task runs. Tasks posted with TaskTraits.CHOREOGRAPHER_FRAME
> will run next time there's a vsync and after all other ready tasks on the thread
> have run.
> 
> I put the trait under base because from what I understand there is some ui/ code
> that needs it but ui/ can't depend on content/.
> 
> Bug: 863341
> Change-Id: Ibcb7a843866c2b2c4f4394ebd18c8ef7aa33b5bc
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1549114
> Commit-Queue: Alex Clarke <alexclarke@chromium.org>
> Reviewed-by: Yaron Friedman <yfriedman@chromium.org>
> Reviewed-by: Sami Kyöstilä <skyostil@chromium.org>
> Reviewed-by: Karolina Soltys <ksolt@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#652215}

TBR=yfriedman@chromium.org,skyostil@chromium.org,alexclarke@chromium.org,ksolt@chromium.org

Change-Id: I2340b5c6c7ce1ac41e87ef689470e798304eb8a8
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 863341
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1574939Reviewed-by: Bret Sepulveda <bsep@chromium.org>
Commit-Queue: Bret Sepulveda <bsep@chromium.org>
Cr-Commit-Position: refs/heads/master@{#652351}

base/BUILD.gn

@@ -3153,7 +3153,6 @@ if (is_android) {
       "android/java/src/org/chromium/base/task/AsyncTask.java",
       "android/java/src/org/chromium/base/task/BackgroundOnlyAsyncTask.java",
       "android/java/src/org/chromium/base/task/DefaultTaskExecutor.java",
-      "android/java/src/org/chromium/base/task/ChoreographerTaskRunner.java",
       "android/java/src/org/chromium/base/task/ChromeThreadPoolExecutor.java",
       "android/java/src/org/chromium/base/task/PostTask.java",
       "android/java/src/org/chromium/base/task/SequencedTaskRunner.java",

base/android/java/src/org/chromium/base/task/ChoreographerTaskRunner.java

-// Copyright 2018 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-package org.chromium.base.task;
-
-import android.view.Choreographer;
-
-/**
- * An adapter that allows PostTask to submit Choreographer frame callbacks which
- * run after the next vsync.
- */
-final class ChoreographerTaskRunner implements SingleThreadTaskRunner {
-    private final Choreographer mChoreographer;
-
-    ChoreographerTaskRunner(Choreographer choreographer) {
-        mChoreographer = choreographer;
-    }
-
-    @Override
-    public boolean belongsToCurrentThread() {
-        try {
-            return mChoreographer == Choreographer.getInstance();
-        } catch (IllegalStateException e) {
-            return false;
-        }
-    }
-
-    @Override
-    public void postTask(Runnable task) {
-        mChoreographer.postFrameCallback(new Choreographer.FrameCallback() {
-            @Override
-            public void doFrame(long frameTimeNanos) {
-                task.run();
-            }
-        });
-    }
-
-    @Override
-    public void destroy() {
-        // NOP
-    }
-
-    @Override
-    public void disableLifetimeCheck() {
-        // NOP
-    }
-
-    @Override
-    public void postDelayedTask(Runnable task, long delayMillis) {
-        mChoreographer.postFrameCallbackDelayed(new Choreographer.FrameCallback() {
-            @Override
-            public void doFrame(long frameTimeNanos) {
-                task.run();
-            }
-        }, delayMillis);
-    }
-
-    @Override
-    public void initNativeTaskRunner() {
-        // NOP
-    }
-}

base/android/java/src/org/chromium/base/task/DefaultTaskExecutor.java

@@ -4,10 +4,6 @@
 
 package org.chromium.base.task;
 
-import android.view.Choreographer;
-
-import org.chromium.base.ThreadUtils;
-
 import java.util.HashMap;
 import java.util.Map;
 
@@ -15,18 +11,15 @@ import java.util.Map;
  * The default {@link TaskExecutor} which maps directly to base::ThreadPool.
  */
 class DefaultTaskExecutor implements TaskExecutor {
-    private final Map<TaskTraits, TaskRunner> mTraitsToRunnerMap = new HashMap<>();
-    private ChoreographerTaskRunner mChoreographerTaskRunner;
+    Map<TaskTraits, TaskRunner> mTraitsToRunnerMap = new HashMap<>();
 
     @Override
     public TaskRunner createTaskRunner(TaskTraits taskTraits) {
-        if (taskTraits.mIsChoreographerFrame) return getChoreographerTaskRunner();
         return new TaskRunnerImpl(taskTraits);
     }
 
     @Override
     public SequencedTaskRunner createSequencedTaskRunner(TaskTraits taskTraits) {
-        if (taskTraits.mIsChoreographerFrame) return getChoreographerTaskRunner();
         return new SequencedTaskRunnerImpl(taskTraits);
     }
 
@@ -36,13 +29,12 @@ class DefaultTaskExecutor implements TaskExecutor {
      */
     @Override
     public SingleThreadTaskRunner createSingleThreadTaskRunner(TaskTraits taskTraits) {
-        if (taskTraits.mIsChoreographerFrame) return getChoreographerTaskRunner();
         // Tasks posted via this API will not execute until after native has started.
         return new SingleThreadTaskRunnerImpl(null, taskTraits);
     }
 
     @Override
-    public synchronized void postDelayedTask(TaskTraits taskTraits, Runnable task, long delay) {
+    public void postDelayedTask(TaskTraits taskTraits, Runnable task, long delay) {
         if (taskTraits.hasExtension()) {
             TaskRunner runner = createTaskRunner(taskTraits);
             runner.postDelayedTask(task, delay);
@@ -65,14 +57,4 @@ class DefaultTaskExecutor implements TaskExecutor {
     public boolean canRunTaskImmediately(TaskTraits traits) {
         return false;
     }
-
-    private synchronized ChoreographerTaskRunner getChoreographerTaskRunner() {
-        // TODO(alexclarke): Migrate to the new Android UI thread trait when available.
-        ChoreographerTaskRunner choreographerTaskRunner =
-                ThreadUtils.runOnUiThreadBlockingNoException(
-                        () -> { return new ChoreographerTaskRunner(Choreographer.getInstance()); });
-
-        mTraitsToRunnerMap.put(TaskTraits.CHOREOGRAPHER_FRAME, choreographerTaskRunner);
-        return choreographerTaskRunner;
-    }
 }

base/android/java/src/org/chromium/base/task/TaskTraits.java

@@ -54,11 +54,6 @@ public class TaskTraits {
     public static final TaskTraits USER_BLOCKING =
             new TaskTraits().taskPriority(TaskPriority.USER_BLOCKING);
 
-    // A bit like requestAnimationFrame, this task will be posted onto the Choreographer
-    // and will be run on the android main thread after the next vsync.
-    public static final TaskTraits CHOREOGRAPHER_FRAME =
-            new TaskTraits().setIsChoreographerFrame(true);
-
     public TaskTraits() {}
 
     private TaskTraits(TaskTraits other) {
@@ -94,11 +89,6 @@ public class TaskTraits {
         return taskTraits;
     }
 
-    private TaskTraits setIsChoreographerFrame(boolean isChoreographerFrame) {
-        mIsChoreographerFrame = isChoreographerFrame;
-        return this;
-    }
-
     // For convenience of the JNI code, we use primitive types only.
     // Note shutdown behavior is not supported on android.
     boolean mPrioritySetExplicitly;
@@ -106,7 +96,6 @@ public class TaskTraits {
     boolean mMayBlock;
     byte mExtensionId = INVALID_EXTENSION_ID;
     byte mExtensionData[];
-    boolean mIsChoreographerFrame;
 
     /**
      * @return true if this task is using some TaskTraits extension.
@@ -163,7 +152,6 @@ public class TaskTraits {
         hash = 37 * hash + (mMayBlock ? 0 : 1);
         hash = 37 * hash + (int) mExtensionId;
         hash = 37 * hash + Arrays.hashCode(mExtensionData);
-        hash = 37 * hash + (mIsChoreographerFrame ? 0 : 1);
         return hash;
     }
 }

base/android/javatests/src/org/chromium/base/task/PostTaskTest.java

@@ -18,7 +18,6 @@ import org.chromium.base.test.task.SchedulerTestHelpers;
 
 import java.util.ArrayList;
 import java.util.List;
-import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.atomic.AtomicBoolean;
 
 /**
@@ -96,34 +95,4 @@ public class PostTaskTest {
             taskQueue.destroy();
         }
     }
-
-    @Test
-    @SmallTest
-    public void testChoreographerFrameTrait() throws Exception {
-        List<Integer> orderList = new ArrayList<>();
-        CountDownLatch latch = new CountDownLatch(2);
-        PostTask.postTask(TaskTraits.CHOREOGRAPHER_FRAME, new Runnable() {
-            @Override
-            public void run() {
-                synchronized (orderList) {
-                    orderList.add(1);
-                    latch.countDown();
-                }
-            }
-        });
-
-        PostTask.postTask(TaskTraits.CHOREOGRAPHER_FRAME, new Runnable() {
-            @Override
-            public void run() {
-                synchronized (orderList) {
-                    orderList.add(2);
-                    latch.countDown();
-                }
-            }
-        });
-
-        latch.await();
-
-        assertThat(orderList, contains(1, 2));
-    }
 }

content/public/android/javatests/src/org/chromium/content/browser/scheduler/UiThreadSchedulerTest.java

@@ -32,7 +32,6 @@ import org.chromium.content_public.browser.test.util.UiThreadSchedulerTestUtils;
 
 import java.util.ArrayList;
 import java.util.List;
-import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.atomic.AtomicBoolean;
 
 /**
@@ -227,52 +226,6 @@ public class UiThreadSchedulerTest {
         Assert.assertTrue(taskExecuted.get());
     }
 
-    @Test
-    @MediumTest
-    public void testChoreographerFrameTrait() throws Exception {
-        List<Integer> orderList = new ArrayList<>();
-        CountDownLatch latch = new CountDownLatch(3);
-        // Post a task so we can run on the UI thread.
-        PostTask.postTask(UiThreadTaskTraits.DEFAULT, new Runnable() {
-            @Override
-            public void run() {
-                PostTask.postTask(TaskTraits.CHOREOGRAPHER_FRAME, new Runnable() {
-                    @Override
-                    public void run() {
-                        synchronized (orderList) {
-                            orderList.add(1);
-                            latch.countDown();
-                        }
-                    }
-                });
-
-                PostTask.postTask(TaskTraits.CHOREOGRAPHER_FRAME, new Runnable() {
-                    @Override
-                    public void run() {
-                        synchronized (orderList) {
-                            orderList.add(2);
-                            latch.countDown();
-                        }
-                    }
-                });
-
-                PostTask.postTask(UiThreadTaskTraits.DEFAULT, new Runnable() {
-                    @Override
-                    public void run() {
-                        synchronized (orderList) {
-                            orderList.add(3);
-                            latch.countDown();
-                        }
-                    }
-                });
-            }
-        });
-        latch.await();
-
-        // The UiThreadTaskTraits.DEFAULT task should run before the two choreographer tasks.
-        assertThat(orderList, contains(3, 1, 2));
-    }
-
     private void startContentMainOnUiThread() {
         final Object lock = new Object();
         final AtomicBoolean uiThreadInitalized = new AtomicBoolean();