Fix bug 10533304 - HD Wallpapers access getProgress on wrong thread

As this value is cached in java in the implementation, we can just skip
the thread check (new apps still get the WebView layer checkThread
exception as intended).

Change-Id: Ic6e75f184a5f73f4841ac6797dfd4f16cf01882f
diff --git a/chromium/java/com/android/webview/chromium/WebViewChromium.java b/chromium/java/com/android/webview/chromium/WebViewChromium.java
index 1fadc35..e70158f 100644
--- a/chromium/java/com/android/webview/chromium/WebViewChromium.java
+++ b/chromium/java/com/android/webview/chromium/WebViewChromium.java
@@ -537,7 +537,7 @@
 
     @Override
     public int getProgress() {
-        checkThread();
+        // No checkThread() because the value is cached java side (workaround for b/10533304).
         return mAwContents.getMostRecentProgress();
     }