webgl: Zero-initialize the SyncToken before calling GenSyncTokenCHROMIUM

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

Index: third_party/WebKit/Source/platform/graphics/gpu/DrawingBuffer.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/gpu/DrawingBuffer.cpp b/third_party/WebKit/Source/platform/graphics/gpu/DrawingBuffer.cpp
index 32416b2befbeabbe7bb114d8140b223cad285ab8..4dc52d9cb4aa155904621fc9c823f31f464831e3 100644
--- a/third_party/WebKit/Source/platform/graphics/gpu/DrawingBuffer.cpp
+++ b/third_party/WebKit/Source/platform/graphics/gpu/DrawingBuffer.cpp
@@ -30,6 +30,7 @@
 
 #include "platform/graphics/gpu/DrawingBuffer.h"
 
+#include "gpu/GLES2/gl2extchromium.h"
 #include "gpu/command_buffer/client/gles2_interface.h"
 #include "gpu/command_buffer/common/capabilities.h"
 #include "platform/RuntimeEnabledFeatures.h"
@@ -554,7 +555,7 @@ bool DrawingBuffer::copyToPlatformTexture(gpu::gles2::GLES2Interface* gl, GLuint
     const GLuint64 fenceSync = gl->InsertFenceSyncCHROMIUM();
 
     gl->Flush();
-    GLbyte syncToken[24];
+    GLbyte syncToken[GL_SYNC_TOKEN_SIZE_CHROMIUM] = { 0 };
     gl->GenSyncTokenCHROMIUM(fenceSync, syncToken);
     m_gl->WaitSyncTokenCHROMIUM(syncToken);