Add sampler related ES3 APIs to command buffer.

gpu/command_buffer/client/gles2_implementation_unittest.cc

Index: gpu/command_buffer/client/gles2_implementation_unittest.cc
diff --git a/gpu/command_buffer/client/gles2_implementation_unittest.cc b/gpu/command_buffer/client/gles2_implementation_unittest.cc
index d772b8e1debc2d13b1e20872206ed6d38b7605ee..31de423c1fe0cfa243aa2f0e7c3f99cf9cfe24d8 100644
--- a/gpu/command_buffer/client/gles2_implementation_unittest.cc
+++ b/gpu/command_buffer/client/gles2_implementation_unittest.cc
@@ -384,6 +384,7 @@ class GLES2ImplementationTest : public testing::Test {
   static const GLuint kFramebuffersStartId = 1;
   static const GLuint kProgramsAndShadersStartId = 1;
   static const GLuint kRenderbuffersStartId = 1;
+  static const GLuint kSamplersStartId = 1;
   static const GLuint kTexturesStartId = 1;
   static const GLuint kQueriesStartId = 1;
   static const GLuint kVertexArraysStartId = 1;
@@ -754,6 +755,7 @@ const GLuint GLES2ImplementationTest::kBuffersStartId;
 const GLuint GLES2ImplementationTest::kFramebuffersStartId;
 const GLuint GLES2ImplementationTest::kProgramsAndShadersStartId;
 const GLuint GLES2ImplementationTest::kRenderbuffersStartId;
+const GLuint GLES2ImplementationTest::kSamplersStartId;
 const GLuint GLES2ImplementationTest::kTexturesStartId;
 const GLuint GLES2ImplementationTest::kQueriesStartId;
 const GLuint GLES2ImplementationTest::kVertexArraysStartId;