Revert "Revert "change SkColorTable to be immutable""

This reverts commit b8162cb840f4cb6002ef68d5ac775c6a122c52a9.

Fixed was call-sites in benches that used the (now gone) setIsOpaque api.

R=scroggo@google.com

Review URL: https://codereview.chromium.org/26572006

git-svn-id: http://skia.googlecode.com/svn/trunk@11695 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/SkGr.cpp b/src/gpu/SkGr.cpp
index 7505d75..0b60ede 100644
--- a/src/gpu/SkGr.cpp
+++ b/src/gpu/SkGr.cpp
@@ -31,7 +31,7 @@
     char* dst = (char*)buffer;
 
     memcpy(dst, ctable->lockColors(), ctable->count() * sizeof(SkPMColor));
-    ctable->unlockColors(false);
+    ctable->unlockColors();
 
     // always skip a full 256 number of entries, even if we memcpy'd fewer
     dst += kGrColorTableSize;