Bug 1433584: Fix misleading nsTArray::SetCapacity documentation to avoid implying that its arg is a delta. r=froydnj

DONTBUILD because comment-only

MozReview-Commit-ID: 8cr092aAJSm

--HG--
extra : rebase_source : 730be11254e22a81cca78911813444b366e16eaa

xpcom/ds/nsTArray.h

@@ -1855,7 +1855,7 @@ public:
   // Allocation
   //
 
-  // This method may increase the capacity of this array object by the
+  // This method may increase the capacity of this array object to the
   // specified amount.  This method may be called in advance of several
   // AppendElement operations to minimize heap re-allocations.  This method
   // will not reduce the number of elements in this array.