pdfviewer: fix typo

experimental/PdfViewer/chop_transparency_main.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBitmap.h"
 #include "SkColorPriv.h"
 #include "SkCommandLineFlags.h"
@@ skipping 25 matching lines @@
     { SkImageEncoder::kJPEG_Type, SkImageDecoder::kJPEG_Format, ".jpg" },
     { SkImageEncoder::kPNG_Type, SkImageDecoder::kPNG_Format, ".png" },
     { SkImageEncoder::kWBMP_Type, SkImageDecoder::kWBMP_Format, ".wbmp" },
     { SkImageEncoder::kWEBP_Type, SkImageDecoder::kWEBP_Format, ".webp" }
 };
 
 SkISize opaqueSize(const SkBitmap& bm) {
     int width = 1;
     int height = 1;
     for (int y = 0 ; y < bm.height(); y++) {
-        for (int x = 0 ; x < bm.height(); x++) {
+        for (int x = 0 ; x < bm.width(); x++) {
             SkColor color = bm.getColor(x, y);
             if (SkColorGetA(color) != 0) {
                 height = y + 1;
                 width = width > (x + 1) ? width : x + 1;
             }
         }
     }
 
     return SkISize::Make(width, height);
 }
@@ skipping 110 matching lines @@
     }
 
     return 0;
 }
 
 #if !defined SK_BUILD_FOR_IOS
 int main(int argc, char * const argv[]) {
     return tool_main(argc, (char**) argv);
 }
 #endif