Revert of [WebView] Add unique visual state request ids. (patchset #4 id:60001...

Revert of [WebView] Add unique visual state request ids. (patchset #4 id:60001 of https://codereview.chromium.org/900303002/)

Reason for revert:
This is breaking some bots, see for example:
https://chromegw.corp.google.com/i/chromium.linux/builders/Android%20Arm64%20Builder%20(dbg)/builds/8923

https://chromegw.corp.google.com/i/chromium.linux/builders/Android%20Builder%20(dbg)/builds/73663

The reason is:
M D ST: Write to static field org.chromium.android_webview.AwContents.sNextVisualStateRequestId from instance method org.chromium.android_webview.AwContents.flushVisualState(AwContents$VisualStateFlushCallback)  At AwContents.java

Original issue's description:
> [WebView] Add unique visual state request ids.
>
> Each flushVisualState request returns a unique id
> that allows callers to match requests with callbacks.
> The reasoning behind is to potentially allow clients
> to reuse VisualStateFlushCallback objects to avoid
> additional java allocations.
>
> BUG=455651
>
> Committed: https://crrev.com/d011b93e7c8f966ba068b0c77c8a1400bdedee88
> Cr-Commit-Position: refs/heads/master@{#315304}

TBR=boliu@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=455651

Review URL: https://codereview.chromium.org/907723004

Cr-Commit-Position: refs/heads/master@{#315321}

android_webview/java/src/org/chromium/android_webview/AwContents.java

@@ -183,18 +183,13 @@ public class AwContents implements SmartClipProvider {
 
     /**
      * Callback used when flushing the visual state, see {@link #flushVisualState}.
-     *
-     * <p>The {@code requestId} is the unique request id returned by
-     * {@link AwContents#flushVisualState} which can be used to match callbacks with requests.
      */
     @VisibleForTesting
     public abstract static class VisualStateFlushCallback {
-        public abstract void onComplete(long requestId);
-        public abstract void onFailure(long requestId);
+        public abstract void onComplete();
+        public abstract void onFailure();
     }
 
-    private static long sNextVisualStateRequestId = 1;
-
     private long mNativeAwContents;
     private final AwBrowserContext mBrowserContext;
     private ViewGroup mContainerView;
@@ -2054,14 +2049,9 @@ public class AwContents implements SmartClipProvider {
      * 1. The DOM tree is committed becoming the pending tree - see ThreadProxy::BeginMainFrame
      * 2. The pending tree is activated becoming the active tree
      * 3. A frame swap happens that draws the active tree into the screen
-     *
-     * @return an unique id that identifies this request. It can be used to match this request
-     * to the corresponding callback to allow reuse of {@link VisualStateFlushCallback} objects.
      */
-    public long flushVisualState(VisualStateFlushCallback callback) {
-        long requestId = sNextVisualStateRequestId++;
-        nativeFlushVisualState(mNativeAwContents, callback, requestId);
-        return requestId;
+    public void flushVisualState(VisualStateFlushCallback callback) {
+        nativeFlushVisualState(mNativeAwContents, callback);
     }
 
     //--------------------------------------------------------------------------------------------
@@ -2174,16 +2164,16 @@ public class AwContents implements SmartClipProvider {
      */
     @CalledByNative
     public void flushVisualStateCallback(
-            final VisualStateFlushCallback callback, final long requestId, final boolean result) {
+            final VisualStateFlushCallback callback, final boolean result) {
         // Posting avoids invoking the callback inside invoking_composite_
         // (see synchronous_compositor_impl.cc and crbug/452530).
         mContainerView.getHandler().post(new Runnable() {
             @Override
             public void run() {
                 if (result) {
-                    callback.onComplete(requestId);
+                    callback.onComplete();
                 } else {
-                    callback.onFailure(requestId);
+                    callback.onFailure();
                 }
             }
         });
@@ -2746,7 +2736,7 @@ public class AwContents implements SmartClipProvider {
     private native long nativeCapturePicture(long nativeAwContents, int width, int height);
     private native void nativeEnableOnNewPicture(long nativeAwContents, boolean enabled);
     private native void nativeFlushVisualState(
-            long nativeAwContents, VisualStateFlushCallback callback, long requestId);
+            long nativeAwContents, VisualStateFlushCallback callback);
     private native void nativeClearView(long nativeAwContents);
     private native void nativeSetExtraHeadersForUrl(long nativeAwContents,
             String url, String extraHeaders);

android_webview/javatests/src/org/chromium/android_webview/test/VisualStateTest.java

@@ -18,6 +18,7 @@ import org.chromium.content_public.browser.LoadUrlParams;
 
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicReference;
 
 /**
  * Visual state related tests.
@@ -25,8 +26,6 @@ import java.util.concurrent.TimeUnit;
 public class VisualStateTest extends AwTestBase {
 
     private TestAwContentsClient mContentsClient = new TestAwContentsClient();
-    private long mExpectedFlushRequestId = -1;
-    private AwContents mAwContents;
 
     @Feature({"AndroidWebView"})
     @SmallTest
@@ -40,16 +39,14 @@ public class VisualStateTest extends AwTestBase {
         runTestOnUiThread(new Runnable() {
             @Override
             public void run() {
-                mExpectedFlushRequestId =
                 awContents.flushVisualState(new AwContents.VisualStateFlushCallback() {
                     @Override
-                            public void onComplete(long requestId) {
-                                assertEquals(mExpectedFlushRequestId, requestId);
+                    public void onComplete() {
                         ch.notifyCalled();
                     }
 
                     @Override
-                            public void onFailure(long requestId) {
+                    public void onFailure() {
                         fail("onFailure received");
                     }
                 });
@@ -68,24 +65,22 @@ public class VisualStateTest extends AwTestBase {
         final LoadUrlParams bluePageUrl = createTestPageUrl("blue");
         final CountDownLatch testFinishedSignal = new CountDownLatch(1);
 
+        final AtomicReference<AwContents> awContentsRef = new AtomicReference<>();
         final AwTestContainerView testView =
                 createAwTestContainerViewOnMainSync(new TestAwContentsClient() {
                     @Override
                     public void onPageFinished(String url) {
                         if (bluePageUrl.getUrl().equals(url)) {
-                            mExpectedFlushRequestId =
-                                    mAwContents.flushVisualState(new VisualStateFlushCallback() {
+                            awContentsRef.get().flushVisualState(new VisualStateFlushCallback() {
                                 @Override
-                                        public void onFailure(long requestId) {
+                                public void onFailure() {
                                     fail("onFailure received");
                                 }
 
                                 @Override
-                                        public void onComplete(long requestId) {
-                                            assertEquals(mExpectedFlushRequestId, requestId);
-                                            Bitmap blueScreenshot =
-                                                    GraphicsTestUtils.drawAwContents(
-                                                            mAwContents, 1, 1);
+                                public void onComplete() {
+                                    Bitmap blueScreenshot = GraphicsTestUtils.drawAwContents(
+                                            awContentsRef.get(), 1, 1);
                                     assertEquals(Color.BLUE, blueScreenshot.getPixel(0, 0));
                                     testFinishedSignal.countDown();
                                 }
@@ -93,19 +88,21 @@ public class VisualStateTest extends AwTestBase {
                         }
                     }
                 });
-        mAwContents = testView.getAwContents();
+        final AwContents awContents = testView.getAwContents();
+        awContentsRef.set(awContents);
 
         runTestOnUiThread(new Runnable() {
             @Override
             public void run() {
-                mAwContents.setBackgroundColor(Color.RED);
-                mAwContents.loadUrl(bluePageUrl);
+                awContents.setBackgroundColor(Color.RED);
+                awContents.loadUrl(bluePageUrl);
 
                 // We have just loaded the blue page, but the graphics pipeline is asynchronous
                 // so at this point the WebView still draws red, ie. the View background color.
                 // Only when the flush callback is received will we know for certain that the
                 // blue page contents are on screen.
-                Bitmap redScreenshot = GraphicsTestUtils.drawAwContents(mAwContents, 1, 1);
+                Bitmap redScreenshot = GraphicsTestUtils.drawAwContents(
+                        awContentsRef.get(), 1, 1);
                 assertEquals(Color.RED, redScreenshot.getPixel(0, 0));
             }
         });

android_webview/native/aw_contents.cc

@@ -1037,27 +1037,22 @@ void AwContents::EnableOnNewPicture(JNIEnv* env,
 namespace {
 void FlushVisualStateCallback(const JavaObjectWeakGlobalRef& java_ref,
                               ScopedJavaGlobalRef<jobject>* callback,
-                              int64 request_id,
                               bool result) {
   JNIEnv* env = AttachCurrentThread();
   ScopedJavaLocalRef<jobject> obj = java_ref.get(env);
   if (obj.is_null())
      return;
-  Java_AwContents_flushVisualStateCallback(env, obj.obj(), callback->obj(),
-                                           request_id, result);
+  Java_AwContents_flushVisualStateCallback(
+      env, obj.obj(), callback->obj(), result);
 }
 }  // namespace
 
-void AwContents::FlushVisualState(JNIEnv* env,
-                                  jobject obj,
-                                  jobject callback,
-                                  int64 request_id) {
+void AwContents::FlushVisualState(JNIEnv* env, jobject obj, jobject callback) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   ScopedJavaGlobalRef<jobject>* j_callback = new ScopedJavaGlobalRef<jobject>();
   j_callback->Reset(env, callback);
-  web_contents_->GetMainFrame()->FlushVisualState(
-      base::Bind(&FlushVisualStateCallback, java_ref_, base::Owned(j_callback),
-                 request_id));
+  web_contents_->GetMainFrame()->FlushVisualState(base::Bind(
+      &FlushVisualStateCallback, java_ref_, base::Owned(j_callback)));
 }
 
 void AwContents::ClearView(JNIEnv* env, jobject obj) {

android_webview/native/aw_contents.h

@@ -129,10 +129,7 @@ class AwContents : public FindHelper::Listener,
   jlong GetAwDrawGLViewContext(JNIEnv* env, jobject obj);
   jlong CapturePicture(JNIEnv* env, jobject obj, int width, int height);
   void EnableOnNewPicture(JNIEnv* env, jobject obj, jboolean enabled);
-  void FlushVisualState(JNIEnv* env,
-                        jobject obj,
-                        jobject callback,
-                        int64 request_id);
+  void FlushVisualState(JNIEnv* env, jobject obj, jobject callback);
   void ClearView(JNIEnv* env, jobject obj);
   void SetExtraHeadersForUrl(JNIEnv* env, jobject obj,
                              jstring url, jstring extra_headers);