Fix warning

BUG=skia:2526
R=caryclark@google.com

Author: bsalomon@google.com

Review URL: https://codereview.chromium.org/270253006

git-svn-id: http://skia.googlecode.com/svn/trunk@14615 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/gl/debug/GrBufferObj.h b/src/gpu/gl/debug/GrBufferObj.h
index 05d3cfdd..5c282ee 100644
--- a/src/gpu/gl/debug/GrBufferObj.h
+++ b/src/gpu/gl/debug/GrBufferObj.h
@@ -41,8 +41,8 @@
     }
     void resetMapped()           { fMapped = false; }
     bool getMapped() const       { return fMapped; }
-    GrGLsizei getMappedOffset() const { return fMappedOffset; }
-    GrGLsizei getMappedLength() const { return fMappedLength; }
+    GrGLintptr getMappedOffset() const { return fMappedOffset; }
+    GrGLsizeiptr getMappedLength() const { return fMappedLength; }
 
     void setBound()              { fBound = true; }
     void resetBound()            { fBound = false; }