Add support for light dumps in SkTraceMemoryDump interface.

include/core/SkTraceMemoryDump.h

Index: include/core/SkTraceMemoryDump.h
diff --git a/include/core/SkTraceMemoryDump.h b/include/core/SkTraceMemoryDump.h
index d7c565f5707b1ed455b6f1d0be5471636f1a38c3..3f3cae56a2c8f0a2bf2a1b5c0fdb906a5b5ec50c 100644
--- a/include/core/SkTraceMemoryDump.h
+++ b/include/core/SkTraceMemoryDump.h
@@ -55,6 +55,11 @@ public:
         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() { }
 };