For #10049: Provide correct seek bar value to screen readers.

app/src/main/java/org/mozilla/fenix/settings/TextPercentageSeekBarPreference.kt

@@ -29,9 +29,11 @@ import android.util.Log
 import android.util.TypedValue
 import android.view.KeyEvent
 import android.view.View
+import android.view.accessibility.AccessibilityNodeInfo
 import android.widget.SeekBar
 import android.widget.SeekBar.OnSeekBarChangeListener
 import android.widget.TextView
+import androidx.core.view.accessibility.AccessibilityNodeInfoCompat.RangeInfoCompat.RANGE_TYPE_PERCENT
 import androidx.preference.Preference
 import androidx.preference.PreferenceViewHolder
 import org.mozilla.fenix.R
@@ -340,6 +342,25 @@ class TextPercentageSeekBarPreference @JvmOverloads constructor(
             val percentage = NumberFormat.getPercentInstance().format(decimalValue)
             mSeekBarValueTextView?.text = percentage
         }
+
+        mSeekBar?.setAccessibilityDelegate(object :
+            View.AccessibilityDelegate() {
+            override fun onInitializeAccessibilityNodeInfo(
+                host: View?,
+                info: AccessibilityNodeInfo?
+            ) {
+                super.onInitializeAccessibilityNodeInfo(host, info)
+                val initialInfo = info?.rangeInfo
+                info?.rangeInfo = initialInfo?.let {
+                    AccessibilityNodeInfo.RangeInfo.obtain(
+                        RANGE_TYPE_PERCENT,
+                        MIN_VALUE.toFloat(),
+                        SEEK_BAR_MAX.toFloat(),
+                        convertCurrentValue(it.current)
+                    )
+                }
+            }
+        })
     }
 
     /**
@@ -433,6 +454,10 @@ class TextPercentageSeekBarPreference @JvmOverloads constructor(
         }
     }
 
+    private fun convertCurrentValue(current: Float): Float {
+        return current * STEP_SIZE + MIN_VALUE.toFloat()
+    }
+
     companion object {
         private const val TAG = "SeekBarPreference"
         private const val STEP_SIZE = 5