Introduce default implementation for TabContentsDelegate::ViewSourceForTab.

chrome/browser/tab_contents/tab_contents.cc

Index: chrome/browser/tab_contents/tab_contents.cc
diff --git a/chrome/browser/tab_contents/tab_contents.cc b/chrome/browser/tab_contents/tab_contents.cc
index 7769d34661382507d1813da9d0f4815bd9416f56..a5cf474b9f1869f46621a2955f08e2d2465e5235 100644
--- a/chrome/browser/tab_contents/tab_contents.cc
+++ b/chrome/browser/tab_contents/tab_contents.cc
@@ -1523,8 +1523,14 @@ int TabContents::GetZoomPercent(bool* enable_increment,
 
 void TabContents::ViewSource()
 {
-  if (delegate_)
-    delegate_->ViewSourceForTab(this);
+  if (!delegate_)
+    return;
+
+  NavigationEntry* active_entry = controller().GetActiveEntry();
+  if (!active_entry)
+    return;
+
+  delegate_->ViewSourceForTab(this, active_entry->url());
 }
 
 // Notifies the RenderWidgetHost instance about the fact that the page is