Revert 132934 - this change seems to break many webgl related layout tests

gpu/command_buffer/client/gles2_implementation.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // A class to emulate GLES2 over command buffers.
 
 #include "../client/gles2_implementation.h"
 
 #include <map>
 #include <set>
@@ skipping 1236 matching lines @@
         unpack_row_length_ = param;
         return;
     case GL_UNPACK_SKIP_ROWS:
         unpack_skip_rows_ = param;
         return;
     case GL_UNPACK_SKIP_PIXELS:
         unpack_skip_pixels_ = param;
         return;
     case GL_UNPACK_FLIP_Y_CHROMIUM:
         unpack_flip_y_ = (param != 0);
-        break;
+        return;
     case GL_PACK_REVERSE_ROW_ORDER_ANGLE:
         pack_reverse_row_order_ =
             IsAnglePackReverseRowOrderAvailable() ? (param != 0) : false;
         break;
     default:
         break;
   }
   helper_->PixelStorei(pname, param);
 }
 
@@ skipping 1865 matching lines @@
     helper_->BindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
   }
 #else
   helper_->DrawElementsInstancedANGLE(
       mode, count, type, ToGLuint(indices), primcount);
 #endif
 }
 
 }  // namespace gles2
 }  // namespace gpu