Revert of Implement support for using GL ES 3.0 with command buffer (patchset #6 id:100001 of https://codereview.chromium.org/1684413003/ )

Reason for revert:
The dependency, ES3 implementation in command_buffer_gles2, got reverted.

Original issue's description:
> Implement support for using GL ES 3.0 with command buffer
>
> Adds a new 'api': --config gpu(api=commandbuffer3) for dm/nanobench.
>
> BUG=skia:4943
> GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1684413003
>
> Committed: https://skia.googlesource.com/skia/+/45c2c8166bbd84a87e29fdd344b39e36e8a28a3f

TBR=bsalomon@google.com
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=skia:4943
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1744963002

Review URL: https://codereview.chromium.org/1744963002
diff --git a/src/gpu/GrContextFactory.cpp b/src/gpu/GrContextFactory.cpp
index 3f7fd4a..b7e4825 100755
--- a/src/gpu/GrContextFactory.cpp
+++ b/src/gpu/GrContextFactory.cpp
@@ -95,11 +95,8 @@
             break;
 #endif
 #if SK_COMMAND_BUFFER
-        case kCommandBufferES2_GLContextType:
-            glCtx.reset(SkCommandBufferGLContext::CreateES2());
-            break;
-        case kCommandBufferES3_GLContextType:
-            glCtx.reset(SkCommandBufferGLContext::CreateES3());
+        case kCommandBuffer_GLContextType:
+            glCtx.reset(SkCommandBufferGLContext::Create());
             break;
 #endif
 #if SK_MESA