[Offline indicator v2] Fix NullPointerException in CompositorViewHolder

Bug: 1048972
Change-Id: I3f06cf95efc9e96679326a41ccf29caa38f0bc9c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2039594
Commit-Queue: Sinan Sahin <sinansahin@google.com>
Reviewed-by: Matthew Jones <mdjones@chromium.org>
Cr-Commit-Position: refs/heads/master@{#738741}

chrome/android/java/src/org/chromium/chrome/browser/compositor/CompositorViewHolder.java

@@ -811,7 +811,7 @@ public class CompositorViewHolder extends FrameLayout
     public void onBottomControlsHeightChanged(
             int bottomControlsHeight, int bottomControlsMinHeight) {
         if (mTabVisible == null) return;
-        getWebContents().notifyBrowserControlsHeightChanged();
+        onBrowserControlsHeightChanged();
         Point viewportSize = getViewportSize();
         setSize(mTabVisible.getWebContents(), mTabVisible.getContentView(), viewportSize.x,
                 viewportSize.y);
@@ -821,13 +821,23 @@ public class CompositorViewHolder extends FrameLayout
     @Override
     public void onTopControlsHeightChanged(int topControlsHeight, int topControlsMinHeight) {
         if (mTabVisible == null) return;
-        getWebContents().notifyBrowserControlsHeightChanged();
+        onBrowserControlsHeightChanged();
         Point viewportSize = getViewportSize();
         setSize(mTabVisible.getWebContents(), mTabVisible.getContentView(), viewportSize.x,
                 viewportSize.y);
         onViewportChanged();
     }
 
+    /**
+     * Notify the {@link WebContents} of the browser controls height changes. Unlike #setSize, this
+     * will make sure the renderer's properties are updated even if the size didn't change.
+     */
+    private void onBrowserControlsHeightChanged() {
+        final WebContents webContents = getWebContents();
+        if (webContents == null) return;
+        webContents.notifyBrowserControlsHeightChanged();
+    }
+
     @Override
     public void onToggleOverlayVideoMode(boolean enabled) {
         if (mCompositorView != null) {