Fix off by one error in last advanceCount in SkFontHost_FreeType.

R=robertphillips@google.com

Review URL: https://codereview.chromium.org/27338003

git-svn-id: http://skia.googlecode.com/svn/trunk@11781 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/ports/SkFontHost_FreeType.cpp b/src/ports/SkFontHost_FreeType.cpp
index 8d6c4d0..eb2f28a 100644
--- a/src/ports/SkFontHost_FreeType.cpp
+++ b/src/ports/SkFontHost_FreeType.cpp
@@ -605,7 +605,7 @@
                 FT_Fixed advances[128];
                 int advanceCount = 128;
                 if (gID + advanceCount > face->num_glyphs)
-                    advanceCount = face->num_glyphs - gID + 1;
+                    advanceCount = face->num_glyphs - gID;
                 getAdvances(face, gID, advanceCount, FT_LOAD_NO_SCALE,
                             advances);
                 for (int i = 0; i < advanceCount; i++) {