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
 
 #include "SkTypes.h"
 
 class SkDiscardableMemory;
 
 /**
  * Interface for memory tracing.
  * This interface is meant to be passed as argument to the memory dump methods of Skia objects.
  * The implementation of this interface is provided by the embedder.
  */
 class SK_API SkTraceMemoryDump {
 public:
     /**
+     * Enum to specify the level of the requested details for the dump from the Skia objects.
+     */
+    enum LevelOfDetails {
+        // Dump only the minimal details to get the total memory usage (Usually just the totals).
+        kLightDumpRequest,

[Primiano Tucci (use gerrit), 2015/09/24 13:10:27]

Remove rquest from the name. Doesn't tell anything useful.
I'd probably go just for kLight and kDetailed

[ssid, 2015/09/24 13:18:49]

I didn't want to make it enum class. So, making it kLightDump.

+
+        // Dump all the details about the memory usage of the caches.
+        kDetailedDumpRequest
+    };
+
+    /**
      *  Appends a new memory dump (i.e. a row) to the trace memory infrastructure.
      *  If dumpName does not exist yet, a new one is created. Otherwise, a new column is appended to
      *  the previously created dump.
      *  Arguments:
      *    dumpName: an absolute, slash-separated, name for the item being dumped
      *        e.g., "skia/CacheX/EntryY".
      *    valueName: a string indicating the name of the column.
      *        e.g., "size", "active_size", "number_of_objects".
      *        This string is supposed to be long lived and is NOT copied.
      *    units: a string indicating the units for the value.
@@ skipping 15 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 the type of details requested in the dump. The skia objects are expected to dump

[Primiano Tucci (use gerrit), 2015/09/24 13:10:27]

THis is a bit difficult to read, but the content is good.
I'd probably reword as

The granularity of the dump is supposed to match the LevelOfDetails argument.
The level of detail must not affect the total size reported, but only
granularity of the child entries.

[ssid, 2015/09/24 13:18:49]

Done.

+     * according to the LevelOfDetails requested and at the same time dump a consistent total usage
+     * across multiple dump requests. Only the detailed information about memory usage can vary.
+     */
+    virtual LevelOfDetails getRequestedDetails() const = 0;
+
 protected:
     virtual ~SkTraceMemoryDump() { }
 };
 
 #endif