Validate UniformBlocks being backed by sufficient data

gpu/command_buffer/service/indexed_buffer_binding_host.cc

 // Copyright (c) 2016 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/indexed_buffer_binding_host.h"
 
 #include "gpu/command_buffer/service/buffer_manager.h"
 
 namespace gpu {
 namespace gles2 {
@@ skipping 177 matching lines @@
 Buffer* IndexedBufferBindingHost::GetBufferBinding(GLuint index) const {
   DCHECK_LT(index, buffer_bindings_.size());
   return buffer_bindings_[index].buffer.get();
 }
 
 GLsizeiptr IndexedBufferBindingHost::GetBufferSize(GLuint index) const {
   DCHECK_LT(index, buffer_bindings_.size());
   return buffer_bindings_[index].size;
 }
 
+GLsizeiptr IndexedBufferBindingHost::GetEffectiveBufferSize(
+    GLuint index) const {
+  DCHECK_LT(index, buffer_bindings_.size());
+  const IndexedBufferBinding& binding = buffer_bindings_[index];
+  if (!binding.buffer.get())
+    return 0;
+  GLsizeiptr full_buffer_size = binding.buffer->size();
+  switch (binding.type) {
+    case kBindBufferBase:
+      return full_buffer_size;
+    case kBindBufferRange:
+      if (binding.offset + binding.size > full_buffer_size)
+        return full_buffer_size - binding.offset;
+      return binding.size;
+    case kBindBufferNone:
+      return 0;
+  }
+  return buffer_bindings_[index].size;
+}
+
 GLintptr IndexedBufferBindingHost::GetBufferStart(GLuint index) const {
   DCHECK_LT(index, buffer_bindings_.size());
   return buffer_bindings_[index].offset;
 }
 
 void IndexedBufferBindingHost::RestoreBindings(
     IndexedBufferBindingHost* prev) {
   size_t limit = max_non_null_binding_index_plus_one_;
   if (prev && prev->max_non_null_binding_index_plus_one_ > limit) {
     limit = prev->max_non_null_binding_index_plus_one_;
@@ skipping 31 matching lines @@
           max_non_null_binding_index_plus_one_ = ii;
           break;
         }
       }
     }
   }
 }
 
 }  // namespace gles2
 }  // namespace gpu