Fix TexImage2D clearing too agressively

gpu/command_buffer/service/gles2_cmd_decoder_unittest_base.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "gpu/command_buffer/service/gles2_cmd_decoder_unittest_base.h"
 
 #include <algorithm>
 #include <string>
 
 #include "base/string_number_conversions.h"
@@ skipping 644 matching lines @@
       .RetiresOnSaturation();
   EXPECT_CALL(*gl_, GetError())
       .WillOnce(Return(GL_NO_ERROR))
       .RetiresOnSaturation();
   TexImage2D cmd;
   cmd.Init(target, level, internal_format, width, height, border, format,
            type, shared_memory_id, shared_memory_offset);
   EXPECT_EQ(error::kNoError, ExecuteCmd(cmd));
 }
 
+void GLES2DecoderTestBase::DoTexImage2DSameSize(
+    GLenum target, GLint level, GLenum internal_format,
+    GLsizei width, GLsizei height, GLint border,
+    GLenum format, GLenum type,
+    uint32 shared_memory_id, uint32 shared_memory_offset) {
+  if (GLES2Decoder::IsAngle())
+  {
+    EXPECT_CALL(*gl_, TexSubImage2D(
+        target, level, 0, 0, width, height, format, type, _))
+        .Times(1)
+        .RetiresOnSaturation();
+  } else {
+    EXPECT_CALL(*gl_, GetError())
+        .WillOnce(Return(GL_NO_ERROR))
+        .RetiresOnSaturation();
+    EXPECT_CALL(*gl_, TexImage2D(target, level, internal_format,
+                                 width, height, border, format, type, _))
+        .Times(1)
+        .RetiresOnSaturation();
+    EXPECT_CALL(*gl_, GetError())
+        .WillOnce(Return(GL_NO_ERROR))
+        .RetiresOnSaturation();
+  }
+  TexImage2D cmd;
+  cmd.Init(target, level, internal_format, width, height, border, format,
+           type, shared_memory_id, shared_memory_offset);
+  EXPECT_EQ(error::kNoError, ExecuteCmd(cmd));
+}
+
 void GLES2DecoderTestBase::DoRenderbufferStorage(
     GLenum target, GLenum internal_format, GLenum actual_format,
     GLsizei width, GLsizei height,  GLenum error) {
   EXPECT_CALL(*gl_, GetError())
       .WillOnce(Return(GL_NO_ERROR))
       .RetiresOnSaturation();
   EXPECT_CALL(*gl_, RenderbufferStorageEXT(
       target, actual_format, width, height))
       .Times(1)
       .RetiresOnSaturation();
@@ skipping 456 matching lines @@
       num_vertices, buffer_id, GL_NO_ERROR);
 }
 
 void GLES2DecoderWithShaderTestBase::SetUp() {
   GLES2DecoderTestBase::SetUp();
   SetupDefaultProgram();
 }
 
 }  // namespace gles2
 }  // namespace gpu