Fix blink of wallpaper seen on opening virtual keyboard

Bug: 805369
Test: Fix failed test and `git cl try`
Change-Id: If77f7d2502cb17891d82914928c031f62d4e5f94
Reviewed-on: https://chromium-review.googlesource.com/954163Reviewed-by: Blake O'Hare <blakeo@chromium.org>
Reviewed-by: Yuichiro Hanada <yhanada@chromium.org>
Commit-Queue: Keigo Oka <oka@chromium.org>
Cr-Commit-Position: refs/heads/master@{#544998}

ui/keyboard/keyboard_controller.cc

@@ -400,6 +400,11 @@ void KeyboardController::HideAnimationFinished() {
   }
 }
 
+void KeyboardController::ShowAnimationFinished() {
+  MarkKeyboardLoadFinished();
+  NotifyKeyboardBoundsChangingAndEnsureCaretInWorkArea();
+}
+
 void KeyboardController::SetContainerBehaviorInternal(
     const ContainerType type) {
   switch (type) {
@@ -642,8 +647,9 @@ void KeyboardController::PopulateKeyboardContent(int64_t display_id,
 
   ui_->ShowKeyboardContainer(container_.get());
 
-  animation_observer_ = std::make_unique<CallbackAnimationObserver>(
-      base::BindOnce(&MarkKeyboardLoadFinished));
+  animation_observer_ =
+      std::make_unique<CallbackAnimationObserver>(base::BindOnce(
+          &KeyboardController::ShowAnimationFinished, base::Unretained(this)));
   ui::ScopedLayerAnimationSettings settings(container_animator);
   settings.AddObserver(animation_observer_.get());
 
@@ -654,7 +660,6 @@ void KeyboardController::PopulateKeyboardContent(int64_t display_id,
   queued_container_type_ = nullptr;
 
   ChangeState(KeyboardControllerState::SHOWN);
-  NotifyKeyboardBoundsChangingAndEnsureCaretInWorkArea();
 }
 
 bool KeyboardController::WillHideKeyboard() const {

ui/keyboard/keyboard_controller.h

@@ -225,8 +225,10 @@ class KEYBOARD_EXPORT KeyboardController : public ui::InputMethodObserver,
   // Returns true if keyboard is scheduled to hide.
   bool WillHideKeyboard() const;
 
-  // Called when the hide animation finishes.
+  // Called when the hide animation finished.
   void HideAnimationFinished();
+  // Called when the show animation finished.
+  void ShowAnimationFinished();
 
   void NotifyKeyboardBoundsChangingAndEnsureCaretInWorkArea();
 

ui/keyboard/keyboard_controller_unittest.cc

@@ -709,11 +709,11 @@ TEST_F(KeyboardControllerAnimationTest, ContainerAnimation) {
   gfx::Transform transform;
   transform.Translate(0, keyboard::kFullWidthKeyboardAnimationDistance);
   EXPECT_EQ(transform, layer->transform());
-  // animation occurs in a cloned layer, so the actual final bounds should
-  // already be applied to the container.
-  EXPECT_EQ(keyboard_container()->bounds(), notified_visible_bounds());
-  EXPECT_EQ(keyboard_container()->bounds(), notified_occluding_bounds());
-  EXPECT_TRUE(notified_is_available());
+  // Actual final bounds should be notified after animation finishes to avoid
+  // flash of background being seen.
+  EXPECT_EQ(gfx::Rect(), notified_visible_bounds());
+  EXPECT_EQ(gfx::Rect(), notified_occluding_bounds());
+  EXPECT_FALSE(notified_is_available());
 
   RunAnimationForLayer(layer);
   EXPECT_TRUE(keyboard_container()->IsVisible());