Add a gpu driver bug workaround to count in all varyings in packing check.

gpu/command_buffer/service/program_manager.h

Index: gpu/command_buffer/service/program_manager.h
diff --git a/gpu/command_buffer/service/program_manager.h b/gpu/command_buffer/service/program_manager.h
index 0da039dc121ec2051a55d98f5933d2edd2f6b984..17995d3af4f28491f0e0e2c57837290b27ed6f7a 100644
--- a/gpu/command_buffer/service/program_manager.h
+++ b/gpu/command_buffer/service/program_manager.h
@@ -34,6 +34,11 @@ class GPU_EXPORT Program : public base::RefCounted<Program> {
  public:
   static const int kMaxAttachedShaders = 2;
 
+  enum VaryingsPackingOption {
+    kCountOnlyStaticallyUsed,
+    kCountAll
+  };
+
   struct UniformInfo {
     UniformInfo();
     UniformInfo(
@@ -201,7 +206,7 @@ class GPU_EXPORT Program : public base::RefCounted<Program> {
 
   // Return false if varyings can't be packed into the max available
   // varying registers.
-  bool CheckVaryingsPacking() const;
+  bool CheckVaryingsPacking(VaryingsPackingOption option) const;
 
   // Visible for testing
   const LocationMap& bind_attrib_location_map() const {
@@ -404,8 +409,6 @@ class GPU_EXPORT ProgramManager {
 
   bool have_context_;
 
-  bool disable_workarounds_;
-
   // Used to clear uniforms.
   std::vector<uint8> zero_;