webgl: Zero-initialize the SyncToken before calling GenSyncTokenCHROMIUM

third_party/WebKit/Source/platform/graphics/gpu/DrawingBuffer.cpp

 /*
  * Copyright (c) 2010, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 551 matching lines @@
     else if (m_wantAlphaChannel && !m_premultipliedAlpha && premultiplyAlpha)
         unpackPremultiplyAlphaNeeded = GL_TRUE;
 
     gl->CopyTextureCHROMIUM(sourceTexture, texture, internalFormat, destType, flipY, unpackPremultiplyAlphaNeeded, unpackUnpremultiplyAlphaNeeded);
 
     gl->DeleteTextures(1, &sourceTexture);
 
     const GLuint64 fenceSync = gl->InsertFenceSyncCHROMIUM();
 
     gl->Flush();
-    GLbyte syncToken[24];
+    GLbyte syncToken[24] = { 0 };

[Ken Russell (switch to Gerrit), 2016/07/18 21:27:05]

Is this code allowed to reference src/gpu/GLES2/gl2extchromium.h at this point?
It would be preferable to change the "24" to GL_SYNC_TOKEN_SIZE_CHROMIUM.

[danakj, 2016/07/18 21:40:35]

Done. Thanks, didn't know that exists.

     gl->GenSyncTokenCHROMIUM(fenceSync, syncToken);
     m_gl->WaitSyncTokenCHROMIUM(syncToken);
 
     return true;
 }
 
 GLuint DrawingBuffer::framebuffer() const
 {
     return m_fbo;
 }
@@ skipping 525 matching lines @@
 
 void DrawingBuffer::restoreTextureBindings()
 {
     // This class potentially modifies the bindings for GL_TEXTURE_2D and
     // GL_TEXTURE_RECTANGLE. Only GL_TEXTURE_2D needs to be restored since
     // the public interface for WebGL does not support GL_TEXTURE_RECTANGLE.
     m_gl->BindTexture(GL_TEXTURE_2D, m_texture2DBinding);
 }
 
 } // namespace blink