Const-ify SkDebugCanvas::getSize().

This is an obviously const method, no reason not to mark it as such.

R=robertphillips@google.com, fmalita@google.com

Author: fmalita@chromium.org

Review URL: https://chromiumcodereview.appspot.com/19289003

git-svn-id: http://skia.googlecode.com/svn/trunk@10094 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/utils/debugger/SkDebugCanvas.h b/src/utils/debugger/SkDebugCanvas.h
index 99df00e..5fb99aa 100644
--- a/src/utils/debugger/SkDebugCanvas.h
+++ b/src/utils/debugger/SkDebugCanvas.h
@@ -120,7 +120,7 @@
     /**
         Returns length of draw command vector.
      */
-    int getSize() {
+    int getSize() const {
         return fCommandVector.count();
     }