Keep allocation size available in minidumps.

cc/tiles/gpu_image_decode_controller.cc

 // Copyright 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 "cc/tiles/gpu_image_decode_controller.h"
 
 #include <inttypes.h>
 
+#include "base/debug/alias.h"
 #include "base/memory/discardable_memory_allocator.h"
 #include "base/memory/ptr_util.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/numerics/safe_math.h"
 #include "base/strings/stringprintf.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/trace_event/memory_dump_manager.h"
 #include "cc/debug/devtools_instrumentation.h"
 #include "cc/output/context_provider.h"
 #include "cc/raster/tile_task.h"
@@ skipping 919 matching lines @@
     return;
   }
 
   TRACE_EVENT0("cc", "GpuImageDecodeController::DecodeImage");
 
   image_data->decode.ResetData();
   std::unique_ptr<base::DiscardableMemory> backing_memory;
   {
     base::AutoUnlock unlock(lock_);
 
+    auto image_data_size = image_data->size;

[vmpstr, 2016/09/16 00:07:41]

nit: size_t instead of auto.

I'm guessing you don't need to use this var in AllocateLockedDiscardable?

[cblume, 2016/09/16 00:13:58]

I plan to remove this code in short order.
I only want to add it to see the value in minidumps coming in from a crash that
is currently live on Canary.

+    base::debug::Alias(&image_data_size);
     backing_memory = base::DiscardableMemoryAllocator::GetInstance()
                          ->AllocateLockedDiscardableMemory(image_data->size);
-    CHECK(backing_memory);
 
     switch (image_data->mode) {
       case DecodedDataMode::CPU: {
         SkImageInfo image_info = CreateImageInfoForDrawImage(
             draw_image, image_data->upload_scale_mip_level);
         // In order to match GPU scaling quality (which uses mip-maps at high
         // quality), we want to use at most medium filter quality for the
         // scale.
         SkPixmap image_pixmap(image_info, backing_memory->data(),
                               image_info.minRowBytes());
@@ skipping 207 matching lines @@
 bool GpuImageDecodeController::DiscardableIsLockedForTesting(
     const DrawImage& image) {
   base::AutoLock lock(lock_);
   auto found = persistent_cache_.Peek(image.image()->uniqueID());
   DCHECK(found != persistent_cache_.end());
   ImageData* image_data = found->second.get();
   return image_data->decode.is_locked();
 }
 
 }  // namespace cc