ui: Cleanup class/struct forward declarations

content/public/android/BUILD.gn

Index: content/public/android/BUILD.gn
diff --git a/content/public/android/BUILD.gn b/content/public/android/BUILD.gn
index f397b7aba062a4bf35d70f1ec768c8581d527052..a9d94c5986c31d76ca8068301232ae6414456044 100644
--- a/content/public/android/BUILD.gn
+++ b/content/public/android/BUILD.gn
@@ -185,6 +185,19 @@ android_library("content_java") {
     "java/src/org/chromium/content/browser/input/ThreadedInputConnection.java",
     "java/src/org/chromium/content/browser/input/ThreadedInputConnectionFactory.java",
     "java/src/org/chromium/content/browser/input/ThreadedInputConnectionProxyView.java",
+    "java/src/org/chromium/content/browser/picker/DateDialogNormalizer.java",
+    "java/src/org/chromium/content/browser/picker/DatePickerDialogCompat.java",
+    "java/src/org/chromium/content/browser/picker/DateTimePickerDialog.java",
+    "java/src/org/chromium/content/browser/picker/DateTimeSuggestion.java",
+    "java/src/org/chromium/content/browser/picker/DateTimeSuggestionListAdapter.java",
+    "java/src/org/chromium/content/browser/picker/InputDialogContainer.java",
+    "java/src/org/chromium/content/browser/picker/MonthPicker.java",
+    "java/src/org/chromium/content/browser/picker/MonthPickerDialog.java",
+    "java/src/org/chromium/content/browser/picker/MultiFieldTimePickerDialog.java",
+    "java/src/org/chromium/content/browser/picker/TwoFieldDatePicker.java",
+    "java/src/org/chromium/content/browser/picker/TwoFieldDatePickerDialog.java",
+    "java/src/org/chromium/content/browser/picker/WeekPicker.java",
+    "java/src/org/chromium/content/browser/picker/WeekPickerDialog.java",
     "java/src/org/chromium/content/browser/shapedetection/ShapeDetectionFactory.java",
     "java/src/org/chromium/content/browser/shapedetection/ShapeDetectionImpl.java",
     "java/src/org/chromium/content/browser/webcontents/WebContentsImpl.java",
@@ -416,6 +429,7 @@ android_library("content_javatests") {
     "javatests/src/org/chromium/content/browser/input/ReplicaInputConnectionTest.java",
     "javatests/src/org/chromium/content/browser/input/SelectPopupTest.java",
     "javatests/src/org/chromium/content/browser/input/TestImeAdapterDelegate.java",
+    "javatests/src/org/chromium/content/browser/picker/DateTimePickerDialogTest.java",
     "javatests/src/org/chromium/content/browser/webcontents/AccessibilitySnapshotTest.java",
     "javatests/src/org/chromium/content/browser/webcontents/WebContentsTest.java",
   ]
@@ -435,6 +449,7 @@ junit_binary("content_junit_tests") {
     "junit/src/org/chromium/content/browser/input/TextInputStateTest.java",
     "junit/src/org/chromium/content/browser/input/ThreadedInputConnectionFactoryTest.java",
     "junit/src/org/chromium/content/browser/input/ThreadedInputConnectionTest.java",
+    "junit/src/org/chromium/content/browser/picker/DateDialogNormalizerTest.java",
     "junit/src/org/chromium/content/browser/BindingManagerImplTest.java",
   ]
   deps = [