Remove command buffer sample app support.

This hasn't compiled for months. We are deemphasizing SampleApp in favor of viewer. Windowed command buffer is not currently something we currently plan to maintain.

TBR=reed@google.com

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2061233002

Review-Url: https://codereview.chromium.org/2061233002
diff --git a/samplecode/SampleApp.cpp b/samplecode/SampleApp.cpp
index e4362c5..971044c 100644
--- a/samplecode/SampleApp.cpp
+++ b/samplecode/SampleApp.cpp
@@ -92,9 +92,7 @@
 };
 #endif  // SAMPLE_PDF_FILE_VIEWER
 
-#if SK_COMMAND_BUFFER
-#define DEFAULT_TO_COMMAND_BUFFER 1
-#elif SK_ANGLE
+#if SK_ANGLE
 //#define DEFAULT_TO_ANGLE 1
 #else
 #define DEFAULT_TO_GPU 0 // if 1 default rendering is on GPU
@@ -211,12 +209,6 @@
                 fBackend = kANGLE_BackEndType;
                 break;
 #endif // SK_ANGLE
-#if SK_COMMAND_BUFFER
-            case kCommandBuffer_DeviceType:
-                // Command buffer is really the only other odd man out :D
-                fBackend = kCommandBuffer_BackEndType;
-                break;
-#endif // SK_COMMAND_BUFFER
             default:
                 SkASSERT(false);
                 break;
@@ -245,11 +237,6 @@
                 glInterface.reset(sk_gpu_test::CreateANGLEGLInterface());
                 break;
 #endif // SK_ANGLE
-#if SK_COMMAND_BUFFER
-            case kCommandBuffer_DeviceType:
-                glInterface.reset(GrGLCreateCommandBufferInterface());
-                break;
-#endif // SK_COMMAND_BUFFER
             default:
                 SkASSERT(false);
                 break;
@@ -744,9 +731,6 @@
 #if SK_ANGLE
         , SampleWindow::kANGLE_DeviceType
 #endif // SK_ANGLE
-#if SK_COMMAND_BUFFER
-        , SampleWindow::kCommandBuffer_DeviceType
-#endif // SK_COMMAND_BUFFER
 #endif // SK_SUPPORT_GPU
     };
     static_assert(SK_ARRAY_COUNT(gCT) == SampleWindow::kDeviceTypeCnt, "array_size_mismatch");
@@ -913,9 +897,6 @@
 #if SK_ANGLE && DEFAULT_TO_ANGLE
     fDeviceType = kANGLE_DeviceType;
 #endif
-#if SK_COMMAND_BUFFER && DEFAULT_TO_COMMAND_BUFFER
-    fDeviceType = kCommandBuffer_DeviceType;
-#endif
 
     fUseClip = false;
     fUsePicture = false;
@@ -964,9 +945,6 @@
 #if SK_ANGLE
                                   "ANGLE",
 #endif
-#if SK_COMMAND_BUFFER
-                                  "Command Buffer",
-#endif
                                   nullptr);
     fAppMenu->assignKeyEquivalentToItem(itemID, 'd');
     itemID = fAppMenu->appendTriState("AA", "AA", sinkID, fAAState);
@@ -2100,9 +2078,6 @@
 #if SK_ANGLE
     "angle: ",
 #endif // SK_ANGLE
-#if SK_COMMAND_BUFFER
-    "command buffer: ",
-#endif // SK_COMMAND_BUFFER
 #endif // SK_SUPPORT_GPU
 };
 static_assert(SK_ARRAY_COUNT(gDeviceTypePrefix) == SampleWindow::kDeviceTypeCnt,