Add compile time checks against longs being used in IPC structs on 32 bit Android.

content/common/gpu/gpu_memory_uma_stats.h

Index: content/common/gpu/gpu_memory_uma_stats.h
diff --git a/content/common/gpu/gpu_memory_uma_stats.h b/content/common/gpu/gpu_memory_uma_stats.h
index 15d874f195c00ea8374cb24018790d3fec0c4161..16c8813544a99769924ffbaa398dda9f0179debc 100644
--- a/content/common/gpu/gpu_memory_uma_stats.h
+++ b/content/common/gpu/gpu_memory_uma_stats.h
@@ -19,13 +19,13 @@ struct GPUMemoryUmaStats {
   }
 
   // The number of bytes currently allocated.
-  size_t bytes_allocated_current;
+  uint32_t bytes_allocated_current;
 
   // The maximum number of bytes ever allocated at once.
-  size_t bytes_allocated_max;
+  uint32_t bytes_allocated_max;
 
   // The number of context groups.
-  size_t context_group_count;
+  uint32_t context_group_count;
 };
 
 }  // namespace content