[TTS][Overlay] Fix content width overflowing narrow panel.

chrome/android/java/src/org/chromium/chrome/browser/compositor/bottombar/OverlayPanel.java

Index: chrome/android/java/src/org/chromium/chrome/browser/compositor/bottombar/OverlayPanel.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/compositor/bottombar/OverlayPanel.java b/chrome/android/java/src/org/chromium/chrome/browser/compositor/bottombar/OverlayPanel.java
index d202dbffbe05f6b86e1c8dffb1548cdfefa197f2..403fbeaca43176e7e382eb3502e72feec78448f8 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/compositor/bottombar/OverlayPanel.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/compositor/bottombar/OverlayPanel.java
@@ -122,6 +122,9 @@ public class OverlayPanel extends OverlayPanelAnimation implements ActivityState
     /** This is used to make sure there is one show request to one close request. */
     private boolean mPanelShown;
 
+    /** Cache the viewport height of the screen to filter SceneOverlay#onSizeChanged events. */
+    private float mViewportHeight;
+
     // ============================================================================================
     // Constructor
     // ============================================================================================
@@ -791,8 +794,14 @@ public class OverlayPanel extends OverlayPanelAnimation implements ActivityState
     @Override
     public void onSizeChanged(float width, float height, float visibleViewportOffsetY,
             int orientation) {
-        resizePanelContentViewCore(width, height);
-        onLayoutChanged(width, height, visibleViewportOffsetY);
+        // Filter events that don't change the viewport height.
+        if (height != mViewportHeight) {
+            // We only care if the orientation is changing, which will certainly change the screen's
+            // viewport height.
+            mViewportHeight = height;
+            resizePanelContentViewCore(width, height);
+            onLayoutChanged(width, height, visibleViewportOffsetY);
+        }
     }
 
     /**