Implement on demand quad rasterization for PicturePiles.

content/common/cc_messages.cc

Index: content/common/cc_messages.cc
diff --git a/content/common/cc_messages.cc b/content/common/cc_messages.cc
index 799fa972fa21e987bb458bb347cf381b45111693..7ffa28cbfa7cd8dac4b8d868bcecbf337d17a4d8 100644
--- a/content/common/cc_messages.cc
+++ b/content/common/cc_messages.cc
@@ -336,6 +336,9 @@ void ParamTraits<cc::RenderPass>::Write(
       case cc::DrawQuad::YUV_VIDEO_CONTENT:
         WriteParam(m, *cc::YUVVideoDrawQuad::MaterialCast(quad));
         break;
+      case cc::DrawQuad::PICTURE_CONTENT:
+        NOTREACHED();

[Leandro Graciá Gil, 2013/03/13 20:30:38]

Cannot write or read PictureDrawQuads because they hold a reference-counted
PicturePileImpl object.

+        break;
       case cc::DrawQuad::INVALID:
         break;
     }
@@ -450,6 +453,9 @@ bool ParamTraits<cc::RenderPass>::Read(
       case cc::DrawQuad::YUV_VIDEO_CONTENT:
         draw_quad = ReadDrawQuad<cc::YUVVideoDrawQuad>(m, iter);
         break;
+      case cc::DrawQuad::PICTURE_CONTENT:
+        NOTREACHED();

[piman, 2013/03/15 03:51:57]

drive-by: Not NOTREACHED since a compromized renderer could still send that, and
possibly try to use it for a privilege escalation.
Return false here instead to refuse the message (rather than continue on
inconsistent data).

[Leandro Graciá Gil, 2013/03/19 17:30:07]

Done.

+        break;
       case cc::DrawQuad::INVALID:
         break;
     }
@@ -529,6 +535,9 @@ void ParamTraits<cc::RenderPass>::Log(
       case cc::DrawQuad::YUV_VIDEO_CONTENT:
         LogParam(*cc::YUVVideoDrawQuad::MaterialCast(quad), l);
         break;
+      case cc::DrawQuad::PICTURE_CONTENT:
+        NOTREACHED();
+        break;
       case cc::DrawQuad::INVALID:
         break;
     }