Don't acquire url on uninitialized Tab in ChromeProvidedSharingOptionsProvider

We now enforce that tab attributes cannot be acquired on an
uninitialized Tab (including Tab#destroy). Adding in a fallback.

Bug: 1117396
Change-Id: I0e8eeec1a982677e64d6d7f82f2fd883c1e0d4ae
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2411160Reviewed-by: Kyle Milka <kmilka@chromium.org>
Commit-Queue: David Maunder <davidjm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#807060}

chrome/browser/share/android/java/src/org/chromium/chrome/browser/share/share_sheet/ChromeProvidedSharingOptionsProvider.java

@@ -97,7 +97,8 @@ class ChromeProvidedSharingOptionsProvider {
         mOrderedFirstPartyOptions = new ArrayList<>();
         initializeFirstPartyOptionsInOrder();
         mChromeOptionShareCallback = chromeOptionShareCallback;
-        mUrl = getUrlToShare(shareParams, chromeShareExtras, mTabProvider.get().getUrl().getSpec());
+        mUrl = getUrlToShare(shareParams, chromeShareExtras,
+                mTabProvider.get().isInitialized() ? mTabProvider.get().getUrl().getSpec() : "");
     }
 
     /**