Revert "Store discard request on the opList and remove GrDiscardOp"

This reverts commit b681a0f1b0acebe36130fd463d14016d48295b97.

Reason for revert: Seems to be messing up some MacMini & Nexus7 bots
Original change's description:
> Store discard request on the opList and remove GrDiscardOp
> 
> Change-Id: Ic1f76bb91c16b23df1fe71c07a4d5ad5abf1dc26
> Reviewed-on: https://skia-review.googlesource.com/32640
> Reviewed-by: Brian Salomon <bsalomon@google.com>
> Commit-Queue: Robert Phillips <robertphillips@google.com>

TBR=egdaniel@google.com,bsalomon@google.com,robertphillips@google.com

Change-Id: I8a89fae7bb11791bd023d7444a074bb34d006fd0
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/32704
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>

1 files changed, 16 insertions, 5 deletions

diff --git a/src/gpu/GrGpuCommandBuffer.h b/src/gpu/GrGpuCommandBuffer.h
index 9e3c00ba5b..31e9a546d5 100644
--- a/src/gpu/GrGpuCommandBuffer.h
+++ b/src/gpu/GrGpuCommandBuffer.h
@@ -30,17 +30,28 @@ struct SkRect;
  */
 class GrGpuCommandBuffer {
 public:
+    enum class LoadOp {
+        kLoad,
+        kClear,
+        kDiscard,
+    };
+
+    enum class StoreOp {
+        kStore,
+        kDiscard,
+    };
+
     struct LoadAndStoreInfo {
-        GrLoadOp  fLoadOp;
-        GrStoreOp fStoreOp;
-        GrColor   fClearColor;
+        LoadOp  fLoadOp;
+        StoreOp fStoreOp;
+        GrColor fClearColor;
     };
 
     // Load-time clears of the stencil buffer are always to 0 so we don't store
     // an 'fStencilClearValue'
     struct StencilLoadAndStoreInfo {
-        GrLoadOp  fLoadOp;
-        GrStoreOp fStoreOp;
+        LoadOp fLoadOp;
+        StoreOp fStoreOp;
     };
 
     GrGpuCommandBuffer(GrRenderTarget* rt, GrSurfaceOrigin origin)