Bug 1364194 - Refresh static toolbar snapshot when page width changes r=botond,jchen

MozReview-Commit-ID: HaQo66j640g

gfx/layers/apz/src/AndroidDynamicToolbarAnimator.cpp

@@ -278,10 +278,15 @@ AndroidDynamicToolbarAnimator::SetCompositionSize(ScreenIntSize aSize)
     return false;
   }
 
-  ScreenIntCoord prevHeight = mCompositorCompositionSize.height;
+  ScreenIntSize prevSize = mCompositorCompositionSize;
   mCompositorCompositionSize = aSize;
 
-  if (prevHeight != aSize.height) {
+  // The width has changed so the static snapshot needs to be updated
+  if ((prevSize.width != aSize.width) && (mToolbarState != eToolbarVisible)) {
+    PostMessage(STATIC_TOOLBAR_NEEDS_UPDATE);
+  }
+
+  if (prevSize.height != aSize.height) {
     UpdateControllerCompositionHeight(aSize.height);
     UpdateFixedLayerMargins();
   }

mobile/android/base/java/org/mozilla/gecko/BrowserApp.java

@@ -1712,7 +1712,11 @@ public class BrowserApp extends GeckoApp
         if (aShow) {
             mBrowserChrome.setVisibility(View.VISIBLE);
         } else {
-            mBrowserChrome.setVisibility(View.GONE);
+            // The chrome needs to be INVISIBLE instead of GONE so that
+            // it will continue update when the layout changes. This
+            // ensures the bitmap generated for the static toolbar
+            // snapshot is the correct size.
+            mBrowserChrome.setVisibility(View.INVISIBLE);
         }
 
         super.toggleChrome(aShow);