Fix crash in CompressedTexSubImage taking 0 offset without pbo

gpu/command_buffer/client/gles2_implementation.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.
 
 // A class to emulate GLES2 over command buffers.
 
 #include "gpu/command_buffer/client/gles2_implementation.h"
 
 #include <GLES2/gl2.h>
 #include <GLES2/gl2ext.h>
@@ skipping 2400 matching lines @@
           buffer->shm_id(), buffer->shm_offset() + offset);
       buffer->set_last_usage_token(helper_->InsertToken());
       CheckGLError();
     }
     return;
   }
   if (bound_pixel_unpack_buffer_) {
     helper_->CompressedTexSubImage2D(
         target, level, xoffset, yoffset, width, height, format, image_size,
         0, ToGLuint(data));
-  } else {
+  } else if (data) {
     SetBucketContents(kResultBucketId, data, image_size);
     helper_->CompressedTexSubImage2DBucket(
         target, level, xoffset, yoffset, width, height, format,
         kResultBucketId);
     // Free the bucket. This is not required but it does free up the memory.
     // and we don't have to wait for the result so from the client's perspective
     // it's cheap.
     helper_->SetBucketSize(kResultBucketId, 0);
+  } else {
+    helper_->CompressedTexSubImage2D(target, level, xoffset, yoffset, width,
+                                     height, format, image_size, 0, 0);
   }
   CheckGLError();
 }
 
 void GLES2Implementation::CompressedTexImage3D(
     GLenum target, GLint level, GLenum internalformat, GLsizei width,
     GLsizei height, GLsizei depth, GLint border, GLsizei image_size,
     const void* data) {
   GPU_CLIENT_SINGLE_THREAD_CHECK();
   GPU_CLIENT_LOG("[" << GetLogPrefix() << "] glCompressedTexImage3D("
@@ skipping 74 matching lines @@
           buffer->shm_id(), buffer->shm_offset() + offset);
       buffer->set_last_usage_token(helper_->InsertToken());
       CheckGLError();
     }
     return;
   }
   if (bound_pixel_unpack_buffer_) {
     helper_->CompressedTexSubImage3D(
         target, level, xoffset, yoffset, zoffset, width, height, depth, format,
         image_size, 0, ToGLuint(data));
-  } else {
+  } else if (data) {
     SetBucketContents(kResultBucketId, data, image_size);
     helper_->CompressedTexSubImage3DBucket(
         target, level, xoffset, yoffset, zoffset, width, height, depth, format,
         kResultBucketId);
     // Free the bucket. This is not required but it does free up the memory.
     // and we don't have to wait for the result so from the client's perspective
     // it's cheap.
     helper_->SetBucketSize(kResultBucketId, 0);
+  } else {
+    helper_->CompressedTexSubImage3D(target, level, xoffset, yoffset, zoffset,
+                                     width, height, depth, format, image_size,
+                                     0, 0);
   }
   CheckGLError();
 }
 
 PixelStoreParams GLES2Implementation::GetUnpackParameters(Dimension dimension) {
   PixelStoreParams params;
   params.alignment = unpack_alignment_;
   params.row_length = unpack_row_length_;
   params.skip_pixels = unpack_skip_pixels_;
   params.skip_rows = unpack_skip_rows_;
@@ skipping 4529 matching lines @@
   CheckGLError();
 }
 
 // Include the auto-generated part of this file. We split this because it means
 // we can easily edit the non-auto generated parts right here in this file
 // instead of having to edit some template or the code generator.
 #include "gpu/command_buffer/client/gles2_implementation_impl_autogen.h"
 
 }  // namespace gles2
 }  // namespace gpu