cc: narrow ChromeOS perf workaround to ARM

cc/resources/resource_provider.cc

 // Copyright 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 "cc/resources/resource_provider.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 1572 matching lines @@
   DCHECK(resource->gl_id);
   DCHECK(resource->allocated);
   // Avoid crashing in release builds if GpuMemoryBuffer allocation fails.
   // http://crbug.com/554541
   if (!resource->gpu_memory_buffer)
     return;
   if (!resource->image_id) {
     GLES2Interface* gl = ContextGL();
     DCHECK(gl);
 
-#if defined(OS_CHROMEOS)
-    // TODO(reveman): GL_COMMANDS_ISSUED_CHROMIUM is used for synchronization
-    // on ChromeOS to avoid some performance issues. This only works with
-    // shared memory backed buffers. crbug.com/436314
+#if defined(OS_CHROMEOS) && defined(ARCH_CPU_ARM_FAMILY)
+    // TODO(reveman): This avoids a performance problem on ARM ChromeOS
+    // devices. This only works with shared memory backed buffers.
+    // crbug.com/580166
     DCHECK_EQ(resource->gpu_memory_buffer->GetHandle().type,
               gfx::SHARED_MEMORY_BUFFER);
 #endif
     resource->image_id = gl->CreateImageCHROMIUM(
         resource->gpu_memory_buffer->AsClientBuffer(), resource->size.width(),
         resource->size.height(), GLInternalFormat(resource->format));
   }
 }
 
 void ResourceProvider::BindImageForSampling(Resource* resource) {
@@ skipping 126 matching lines @@
 
     const int kImportance = 2;
     pmd->CreateSharedGlobalAllocatorDump(guid);
     pmd->AddOwnershipEdge(dump->guid(), guid, kImportance);
   }
 
   return true;
 }
 
 }  // namespace cc