Expose MemoryCoordinator's global budget information.

content/common/child_memory_coordinator.mojom

Index: content/common/child_memory_coordinator.mojom
diff --git a/content/common/child_memory_coordinator.mojom b/content/common/child_memory_coordinator.mojom
index 0a20b7fbd3fce8589a4d74b99cfa8c83f3bf40ba..107d24e90c6f96c387abc459f8b3fd1195da4ba3 100644
--- a/content/common/child_memory_coordinator.mojom
+++ b/content/common/child_memory_coordinator.mojom
@@ -20,4 +20,13 @@ interface ChildMemoryCoordinator {
   // Called when the central memory coodinator changes the state for child
   // processes.
   OnStateChange(MemoryState state);
+
+  // Called by the central memory coordinator to communicate budget changes
+  // to the child process. This communicates the global budget which is
+  // usable in aggregate by all Chrome processes. This indicates how many MB
+  // of memory are remaining for Chrome processes to use before the memory
+  // coordinator will take efforts to reclaim memory. A negative amount
+  // indicates that the coordinator is actively trying to reclaim that much
+  // memory.
+  SetRemainingGlobalBudget(int64 remaining_global_budget_mb);
 };