Bug 1437988 - [2.0] Use progress tracking events for custom tabs progress bar. r=droeh

mobile/android/base/java/org/mozilla/gecko/customtabs/CustomTabsActivity.java

@@ -114,7 +114,6 @@ public class CustomTabsActivity extends AppCompatActivity
         doorhangerOverlay = findViewById(R.id.custom_tabs_doorhanger_overlay);
 
         mProgressView = (ProgressBar) findViewById(R.id.page_progress);
-        updateProgress(10);
         final Toolbar toolbar = (Toolbar) findViewById(R.id.actionbar);
         setSupportActionBar(toolbar);
         final ActionBar actionBar = getSupportActionBar();
@@ -596,7 +595,6 @@ public class CustomTabsActivity extends AppCompatActivity
     public void onLocationChange(GeckoSession session, String url) {
         mCurrentUrl = url;
         updateActionBar();
-        updateProgress(60);
     }
 
     @Override
@@ -663,18 +661,21 @@ public class CustomTabsActivity extends AppCompatActivity
         mCanStop = true;
         updateActionBar();
         updateCanStop();
-        updateProgress(20);
     }
 
     @Override
     public void onPageStop(GeckoSession session, boolean success) {
         mCanStop = false;
         updateCanStop();
-        updateProgress(100);
     }
 
     @Override
     public void onProgressChange(GeckoSession session, int progress) {
+        if (progress == 100) {
+            mCanStop = false;
+            updateCanStop();
+        }
+        updateProgress(progress);
     }
 
     @Override