Rebind to correct backbuffer after clearing READ buffer.

gpu/command_buffer/service/gles2_cmd_decoder.cc

Index: gpu/command_buffer/service/gles2_cmd_decoder.cc
diff --git a/gpu/command_buffer/service/gles2_cmd_decoder.cc b/gpu/command_buffer/service/gles2_cmd_decoder.cc
index e2d60dab09107d97cbc3c1cecc01539616ce9fda..3de264c99575c30e669785e85d7d26b6a9349d97 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder.cc
+++ b/gpu/command_buffer/service/gles2_cmd_decoder.cc
@@ -3979,10 +3979,11 @@ void GLES2DecoderImpl::ClearUnclearedAttachments(
 
   if (target == GL_READ_FRAMEBUFFER_EXT) {
     glBindFramebufferEXT(GL_READ_FRAMEBUFFER_EXT, info->service_id());
-    FramebufferManager::FramebufferInfo*framebuffer =
-        GetFramebufferInfoForTarget(GL_READ_FRAMEBUFFER);
-    glBindFramebufferEXT(
-        GL_DRAW_FRAMEBUFFER_EXT, framebuffer ? framebuffer->service_id() : 0);
+    FramebufferManager::FramebufferInfo* framebuffer =
+        GetFramebufferInfoForTarget(GL_DRAW_FRAMEBUFFER_EXT);
+    GLuint service_id =
+        framebuffer ? framebuffer->service_id() : GetBackbufferServiceId();
+    glBindFramebufferEXT(GL_DRAW_FRAMEBUFFER_EXT, service_id);
   }
 }