WebGL: Three small fixes to Image CHROMIUM logic.

third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.cpp

 /*
  * Copyright (C) 2009 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 1229 matching lines @@
     }
     if (contextAttributes.get().stencil() || drawingBuffer()->hasImplicitStencilBuffer()) {
         if (combinedClear && (mask & GL_STENCIL_BUFFER_BIT))
             contextGL()->ClearStencil(m_clearStencil & m_stencilMask);
         else
             contextGL()->ClearStencil(0);
         clearMask |= GL_STENCIL_BUFFER_BIT;
         contextGL()->StencilMaskSeparate(GL_FRONT, 0xFFFFFFFF);
     }
 
+    contextGL()->ColorMask(true, true, true, !drawingBuffer()->defaultBufferRequiresAlphaChannelToBePreserved());
     drawingBuffer()->clearFramebuffers(clearMask);
 
     restoreStateAfterClear();
     drawingBuffer()->restoreFramebufferBindings();
     drawingBuffer()->setBufferClearNeeded(false);
 
     return combinedClear ? CombinedClear : JustClear;
 }
 
 void WebGLRenderingContextBase::restoreStateAfterClear()
@@ skipping 5174 matching lines @@
         contextGL()->PixelStorei(GL_UNPACK_ALIGNMENT, 1);
 }
 
 void WebGLRenderingContextBase::restoreUnpackParameters()
 {
     if (m_unpackAlignment != 1)
         contextGL()->PixelStorei(GL_UNPACK_ALIGNMENT, m_unpackAlignment);
 }
 
 } // namespace blink