Fix bottom toolbar showing while in fullscreen

This patch fixes an issue with the bottom toolbar when entering
fullscreen while the keyboard is visible. To conserve space while
the keyboard is showing, the bottom controls height is set to 0
and reset when the keyboard is hidden. This does not account for
fullscreen mode, so when the keyboard is hidden it blindly tells
the controls to become visible again. This patch adds logic to
update the bottom toolbar when the controls height is restored
and only conditionally shows the toolbar if another browser feature
isn't blocking it.

Bug: 872323
Change-Id: Ic3f33fcd7ae207415a5d36b56dba86ec216d3a51
Reviewed-on: https://chromium-review.googlesource.com/1167997Reviewed-by: Pedro Amaral <amaralp@chromium.org>
Commit-Queue: Matthew Jones <mdjones@chromium.org>
Cr-Commit-Position: refs/heads/master@{#581903}

chrome/android/java/src/org/chromium/chrome/browser/toolbar/BottomToolbarMediator.java

@@ -115,10 +115,10 @@ class BottomToolbarMediator implements ContextualSearchObserver, FullscreenListe
     @Override
     public void onControlsOffsetChanged(float topOffset, float bottomOffset, boolean needsAnimate) {
         mModel.setValue(BottomToolbarModel.Y_OFFSET, (int) bottomOffset);
-        if (bottomOffset > 0) {
+        if (bottomOffset > 0 || mFullscreenManager.getBottomControlsHeight() == 0) {
             mModel.setValue(BottomToolbarModel.ANDROID_VIEW_VISIBLE, false);
         } else {
-            mModel.setValue(BottomToolbarModel.ANDROID_VIEW_VISIBLE, true);
+            tryShowingAndroidView();
         }
     }
 
@@ -157,30 +157,38 @@ class BottomToolbarMediator implements ContextualSearchObserver, FullscreenListe
 
     @Override
     public void onHideContextualSearch() {
-        // If the scroll offset for the toolbar is non-zero, it needs to remain hidden after
-        // contextual search is hidden.
-        if (mModel.getValue(BottomToolbarModel.Y_OFFSET) != 0) return;
-        mModel.setValue(BottomToolbarModel.ANDROID_VIEW_VISIBLE, true);
+        tryShowingAndroidView();
     }
 
     @Override
     public void keyboardVisibilityChanged(boolean isShowing) {
         // The toolbars are force shown when the keyboard is visible, so we can blindly set
         // the bottom toolbar view to visible or invisible regardless of the previous state.
-        ChromeFullscreenManager fullscreenManager =
-                mModel.getValue(BottomToolbarModel.LAYOUT_MANAGER).getFullscreenManager();
         if (isShowing) {
-            mBottomToolbarHeightBeforeHide = fullscreenManager.getBottomControlsHeight();
+            mBottomToolbarHeightBeforeHide = mFullscreenManager.getBottomControlsHeight();
             mModel.setValue(BottomToolbarModel.ANDROID_VIEW_VISIBLE, false);
             mModel.setValue(BottomToolbarModel.COMPOSITED_VIEW_VISIBLE, false);
-            fullscreenManager.setBottomControlsHeight(0);
+            mFullscreenManager.setBottomControlsHeight(0);
         } else {
-            fullscreenManager.setBottomControlsHeight(mBottomToolbarHeightBeforeHide);
-            mModel.setValue(BottomToolbarModel.ANDROID_VIEW_VISIBLE, true);
+            mFullscreenManager.setBottomControlsHeight(mBottomToolbarHeightBeforeHide);
+            tryShowingAndroidView();
+            mModel.setValue(
+                    BottomToolbarModel.Y_OFFSET, (int) mFullscreenManager.getBottomControlOffset());
             mModel.setValue(BottomToolbarModel.COMPOSITED_VIEW_VISIBLE, true);
         }
     }
 
+    /**
+     * Try showing the toolbar's Android view after it has been hidden. This accounts for cases
+     * where a browser signal would ordinarily re-show the view, but others still require it to be
+     * hidden.
+     */
+    private void tryShowingAndroidView() {
+        if (mFullscreenManager.getBottomControlOffset() > 0) return;
+        if (mModel.getValue(BottomToolbarModel.Y_OFFSET) != 0) return;
+        mModel.setValue(BottomToolbarModel.ANDROID_VIEW_VISIBLE, true);
+    }
+
     void setLayoutManager(LayoutManager layoutManager) {
         mModel.setValue(BottomToolbarModel.LAYOUT_MANAGER, layoutManager);
         layoutManager.addSceneChangeObserver(this);