Enable WebGL rendering into ImageCHROMIUM, backed by a scanout buffer to enable overlay suppor…

public/platform/WebExternalTextureMailbox.h

Index: public/platform/WebExternalTextureMailbox.h
diff --git a/public/platform/WebExternalTextureMailbox.h b/public/platform/WebExternalTextureMailbox.h
index 423e4179b0320b4cab87dcc75289cc102774a96c..c596d572162bfd767be220ad2af9d84e33820242 100644
--- a/public/platform/WebExternalTextureMailbox.h
+++ b/public/platform/WebExternalTextureMailbox.h
@@ -36,9 +36,11 @@ namespace blink {
 struct WebExternalTextureMailbox {
     signed char name[64];
     unsigned syncPoint;
+    bool allowOverlay;

[Ken Russell (switch to Gerrit), 2014/05/14 22:11:33]

Should this be "useOverlay"? "allow" gives the impression that an overlay might
be allocated or might not be allocated.

[alexst (slow to review), 2014/05/14 22:29:55]

"allow" is actually closer to reality because we are enabling a possibility of
an overlay. We may not use one if we run out of available planes or if webgl
stops painting (more efficient to not re-scan the same static buffer)

 
     WebExternalTextureMailbox()
         : syncPoint(0)
+        , allowOverlay(false)
     {
         memset(name, 0, sizeof(name));
     }