From d9cb337ff4a744969259fa8cac73512f4f5fe2a4 Mon Sep 17 00:00:00 2001
From: Patrick Noland <pnoland@google.com>
Date: Thu, 11 Dec 2025 15:20:05 -0800
Subject: [PATCH] Force relayout for tab-driven constraint changes

This logic currently only runs for browserdelegate-driven constraint
changes, which misses e.g. form-field focus driven SHOWN.

Bug: 467448811
Change-Id: I5662353216c8faea84a98e2f3edfa584cd6adf2c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7253201
Reviewed-by: Wenyu Fu <wenyufu@chromium.org>
Commit-Queue: Patrick Noland <pnoland@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1557729}
---

diff --git a/chrome/android/java/src/org/chromium/chrome/browser/fullscreen/BrowserControlsManager.java b/chrome/android/java/src/org/chromium/chrome/browser/fullscreen/BrowserControlsManager.java
index 1f6a93c..9a78efa6 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/fullscreen/BrowserControlsManager.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/fullscreen/BrowserControlsManager.java
@@ -222,47 +222,7 @@
         mBrowserVisibilityDelegate =
                 new BrowserStateBrowserControlsVisibilityDelegate(
                         mHtmlApiHandler.getPersistentFullscreenModeSupplier());
-        mBrowserVisibilityDelegate.addObserver(
-                (constraints) -> {
-                    if (constraints == BrowserControlsState.SHOWN) {
-                        // When compositor can drive the animation to show controls, do not call
-                        // setPositionsForTabToNonFullscreen to avoid control offset being forced
-                        // set to 0 before the render-driven animation kicks in.
-                        boolean allowRenderDrivenShowConstraint =
-                                ChromeFeatureList.sBrowserControlsRenderDrivenShowConstraint
-                                        .isEnabled();
-                        boolean renderDrivenShowConstraint =
-                                allowRenderDrivenShowConstraint
-                                        && canAnimateNativeBrowserControls();
-                        if (!renderDrivenShowConstraint) {
-                            setPositionsForTabToNonFullscreen();
-                        }
-
-                        // TODO(https://crbug.com/449011189): Maybe cleanup
-                        if (allowRenderDrivenShowConstraint) {
-                            RecordHistogram.recordBooleanHistogram(
-                                    "Android.BrowserControls.RenderDrivenShowConstraint",
-                                    renderDrivenShowConstraint);
-                        }
-
-                        // If controls become locked, it's possible we've previously delayed
-                        // actually setting visibility until a touch event is over. In this case, we
-                        // need to trigger an update again now, which should go through due to
-                        // constraints.
-                        scheduleVisibilityUpdate();
-                    }
-
-                    // From https://crbug.com/452885338, https://crbug.com/461532432: When changing
-                    // controls visibility when exiting fullscreen, the visibility change might not
-                    // honor a redraw. We do this through forcing a relayout to avoid the toolbar
-                    // remains hidden.
-                    if ((constraints == BrowserControlsState.SHOWN
-                                    || constraints == BrowserControlsState.BOTH)
-                            && getAndroidControlsVisibility() != View.VISIBLE) {
-                        mForceRelayoutOnVisibilityChange = true;
-                        scheduleVisibilityUpdate();
-                    }
-                });
+        mBrowserVisibilityDelegate.addObserver(this::onConstraintsChanged);
     }
 
     /**
@@ -354,9 +314,10 @@
                                 new OffsetTagConstraints(
                                         0, 0, -(mTopControlsHeight + hairlineHeight), 0);
 
+                        onConstraintsChanged(constraints);
                         // Notify observers of changes before passing tags to native so observers
                         // can set their relevant fields in offsetTagsInfo.
-                        notifyConstraintsChanged(oldOffsetTagsInfo, offsetTagsInfo, constraints);
+                        notifyOffsetTagsChanged(oldOffsetTagsInfo, offsetTagsInfo, constraints);
 
                         offsetTagsInfo
                                 .getConstraints()
@@ -850,7 +811,9 @@
             return;
         }
         final int desiredVisibility = shouldShowAndroidControls() ? View.VISIBLE : View.INVISIBLE;
-        if (mControlContainer.getView().getVisibility() == desiredVisibility) return;
+        if (mControlContainer.getView().getVisibility() == desiredVisibility) {
+            return;
+        }
         mControlContainer.getView().removeCallbacks(mUpdateVisibilityRunnable);
         mControlContainer.getView().postOnAnimation(mUpdateVisibilityRunnable);
     }
@@ -1022,7 +985,45 @@
         }
     }
 
-    private void notifyConstraintsChanged(
+    private void onConstraintsChanged(@BrowserControlsState int constraints) {
+        if (constraints == BrowserControlsState.SHOWN) {
+            // When compositor can drive the animation to show controls, do not call
+            // setPositionsForTabToNonFullscreen to avoid control offset being forced
+            // set to 0 before the render-driven animation kicks in.
+            boolean allowRenderDrivenShowConstraint =
+                    ChromeFeatureList.sBrowserControlsRenderDrivenShowConstraint.isEnabled();
+            boolean renderDrivenShowConstraint =
+                    allowRenderDrivenShowConstraint && canAnimateNativeBrowserControls();
+            if (!renderDrivenShowConstraint) {
+                setPositionsForTabToNonFullscreen();
+            }
+
+            // TODO(https://crbug.com/449011189): Maybe cleanup
+            if (allowRenderDrivenShowConstraint) {
+                RecordHistogram.recordBooleanHistogram(
+                        "Android.BrowserControls.RenderDrivenShowConstraint",
+                        renderDrivenShowConstraint);
+            }
+
+            // If controls become locked, it's possible we've previously delayed
+            // actually setting visibility until a touch event is over. In this case, we
+            // need to trigger an update again now, which should go through due to
+            // constraints.
+            scheduleVisibilityUpdate();
+        }
+
+        // From https://crbug.com/452885338, https://crbug.com/461532432: When changing
+        // controls visibility when exiting fullscreen, the visibility change might not
+        // honor a redraw. We do this through forcing a relayout to avoid the toolbar
+        // remains hidden.
+        if ((constraints == BrowserControlsState.SHOWN || constraints == BrowserControlsState.BOTH)
+                && getAndroidControlsVisibility() != View.VISIBLE) {
+            mForceRelayoutOnVisibilityChange = true;
+            scheduleVisibilityUpdate();
+        }
+    }
+
+    private void notifyOffsetTagsChanged(
             BrowserControlsOffsetTagsInfo oldOffsetTagsInfo,
             BrowserControlsOffsetTagsInfo offsetTagsInfo,
             @BrowserControlsState int constraints) {
diff --git a/chrome/android/junit/src/org/chromium/chrome/browser/fullscreen/BrowserControlsManagerUnitTest.java b/chrome/android/junit/src/org/chromium/chrome/browser/fullscreen/BrowserControlsManagerUnitTest.java
index 60399a7..e1d8392 100644
--- a/chrome/android/junit/src/org/chromium/chrome/browser/fullscreen/BrowserControlsManagerUnitTest.java
+++ b/chrome/android/junit/src/org/chromium/chrome/browser/fullscreen/BrowserControlsManagerUnitTest.java
@@ -54,6 +54,7 @@
 import org.chromium.cc.input.BrowserControlsState;
 import org.chromium.chrome.R;
 import org.chromium.chrome.browser.ActivityTabProvider;
+import org.chromium.chrome.browser.browser_controls.BrowserControlsOffsetTagsInfo;
 import org.chromium.chrome.browser.browser_controls.BrowserControlsStateProvider;
 import org.chromium.chrome.browser.browser_controls.BrowserControlsStateProvider.ControlsPosition;
 import org.chromium.chrome.browser.browser_controls.BrowserStateBrowserControlsVisibilityDelegate;
@@ -784,6 +785,28 @@
                         anyBoolean());
     }
 
+    @Test
+    public void testConstraintChangeFromTab() {
+        remakeWithoutSpy();
+        notifyAddTab(mTab);
+        mActivityTabProvider.setForTesting(mTab);
+        // Put the control container in a hidden state and bottom-positioned.
+        mBrowserControlsManager.setControlsPosition(
+                ControlsPosition.BOTTOM, 0, 0, 0, TOOLBAR_HEIGHT, 10, TOOLBAR_HEIGHT);
+        ShadowLooper.idleMainLooper();
+        Mockito.clearInvocations(mContainerView);
+        // Locking the controls via the TabControlsObserver should check for forced relayout.
+        mBrowserControlsManager
+                .getTabControlsObserverForTesting()
+                .onOffsetTagsInfoChanged(
+                        mTab,
+                        new BrowserControlsOffsetTagsInfo(),
+                        new BrowserControlsOffsetTagsInfo(),
+                        BrowserControlsState.SHOWN);
+        ShadowLooper.idleMainLooper();
+        verify(mContainerView).requestLayout();
+    }
+
     private void verifyUpdateOffsetTagDefinitions(
             OffsetTagConstraints top, OffsetTagConstraints content, OffsetTagConstraints bottom) {
         BrowserControlsOffsetTagConstraints expectedConstraints =