aw: Add versions to public function tables

android_webview/public/browser/draw_gl.h

Index: android_webview/public/browser/draw_gl.h
diff --git a/android_webview/public/browser/draw_gl.h b/android_webview/public/browser/draw_gl.h
index 4a43523593ac151fd2c67e580dbdfd37be52cb14..d62375fc5bdeac0fd632bd00ff4c86e75667ee15 100644
--- a/android_webview/public/browser/draw_gl.h
+++ b/android_webview/public/browser/draw_gl.h
@@ -86,8 +86,11 @@ typedef void* AwGetNativeBufferFunction(long buffer_id);
 // Called to get the stride of the buffer
 typedef unsigned int AwGetStrideFunction(long buffer_id);
 
+static const int kAwDrawGLFunctionTableVersion = 1;
+
 // Set of functions used in rendering in hardware mode
 struct AwDrawGLFunctionTable {
+  int version;
   AwCreateGraphicBufferFunction* create_graphic_buffer;
   AwReleaseGraphicBufferFunction* release_graphic_buffer;
   AwMapFunction* map;