Add immediate mode option for gpu configs in dm

include/gpu/GrContextOptions.h

Index: include/gpu/GrContextOptions.h
diff --git a/include/gpu/GrContextOptions.h b/include/gpu/GrContextOptions.h
index 7c723a8434ccbbc25e80f889a80204f89f98ed71..6b93927af7dd8d804fe6b1dbb4c12a317b800167 100644
--- a/include/gpu/GrContextOptions.h
+++ b/include/gpu/GrContextOptions.h
@@ -18,7 +18,8 @@ struct GrContextOptions {
         , fMinTextureSizeOverride(0)
         , fSuppressDualSourceBlending(false)
         , fGeometryBufferMapThreshold(-1)
-        , fUseDrawInsteadOfPartialRenderTargetWrite(false) {}
+        , fUseDrawInsteadOfPartialRenderTargetWrite(false)
+        , fImmediateMode(false) {}
 
     // EXPERIMENTAL
     // May be removed in the future, or may become standard depending
@@ -43,6 +44,10 @@ struct GrContextOptions {
 
     /** some gpus have problems with partial writes of the rendertarget */
     bool fUseDrawInsteadOfPartialRenderTargetWrite;
+
+    /** The GrContext operates in immedidate mode. It will issue all draws to the backend API
+        immediately. Intended to ease debugging. */
+    bool fImmediateMode;
 };
 
 #endif