Ensure scrim was shown prior to hiding

This patch adds a flag to the ToolbarManager to check whether the
scrim was actually shown since the timing of the show request can
vary.

Bug: 1065480
Change-Id: I254d1425c58bfe05ae97a609097a2e75b6908933
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2129847Reviewed-by: Theresa  <twellington@chromium.org>
Commit-Queue: Matthew Jones <mdjones@chromium.org>
Cr-Commit-Position: refs/heads/master@{#754962}

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

@@ -299,6 +299,9 @@ public class ToolbarManager implements ToolbarTabController, UrlFocusChangeListe
             /** The params used to control how the scrim behaves when shown for the omnibox. */
             private PropertyModel mScrimModel;
 
+            /** Whether the scrim was shown on focus. */
+            private boolean mScrimShown;
+
             /** The light color to use for the scrim on the NTP. */
             private int mLightScrimColor;
 
@@ -353,8 +356,10 @@ public class ToolbarManager implements ToolbarTabController, UrlFocusChangeListe
 
                 if (hasFocus && !showScrimAfterAnimationCompletes()) {
                     mScrimCoordinator.showScrim(mScrimModel);
-                } else if (!hasFocus) {
+                    mScrimShown = true;
+                } else if (!hasFocus && mScrimShown) {
                     mScrimCoordinator.hideScrim(true);
+                    mScrimShown = false;
                 }
             }
 
@@ -362,6 +367,7 @@ public class ToolbarManager implements ToolbarTabController, UrlFocusChangeListe
             public void onUrlAnimationFinished(boolean hasFocus) {
                 if (hasFocus && showScrimAfterAnimationCompletes()) {
                     mScrimCoordinator.showScrim(mScrimModel);
+                    mScrimShown = true;
                 }
             }