Add support for light dumps in SkTraceMemoryDump interface.

include/core/SkTraceMemoryDump.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkTraceMemoryDump_DEFINED
 #define SkTraceMemoryDump_DEFINED
 
@@ skipping 37 matching lines @@
                                   const char* backingType,
                                   const char* backingObjectId) = 0;
 
     /**
      * Specialization for memory backed by discardable memory.
      */
     virtual void setDiscardableMemoryBacking(
         const char* dumpName,
         const SkDiscardableMemory& discardableMemoryObject) = 0;
 
+    /**
+     * Returns true if only the memory totals of the caches are required to be dumped.
+     */
+    virtual bool isLightDump() const = 0;

[reed1, 2015/09/10 19:44:37]

a little odd that the comment specifics (only memory totals) is not some how
part of the name -- i.e. that this method *requires* a comment for callers (and
implementors) to guess what it means.

Do you anticipate future refinements? I wonder if soon a bitfield or other
expansion will be desired:
enum Required {
    kMemoryTotals = 1 << 0,
    kDiscardableDetails = 1 << 1,
    kOwnershipTracing = 1 << 2,    // just making this one up
    ...
};

virtual Required getRequiredDetails() const = 0;

Just a thought.

+
 protected:
     virtual ~SkTraceMemoryDump() { }
 };
 
 #endif