Make SkDeferredCanvas query SkGPipeWriter for space allocated for bitmaps.

SkGPipe now has a method to report how much memory is used for its shared heap.

BUG=http://code.google.com/p/skia/issues/detail?id=738
TEST=DeferredCanvasTest

Review URL: https://codereview.appspot.com/6445046

git-svn-id: http://skia.googlecode.com/svn/trunk@4791 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/tests/DeferredCanvasTest.cpp b/tests/DeferredCanvasTest.cpp
index 0fee180..7a8ed9d 100644
--- a/tests/DeferredCanvasTest.cpp
+++ b/tests/DeferredCanvasTest.cpp
@@ -212,7 +212,7 @@
 
     // SkPicture path is not fixed
 #if SK_DEFERRED_CANVAS_USES_GPIPE
-    REPORTER_ASSERT(reporter, mockDevice.fDrawBitmapCallCount == 3);
+    REPORTER_ASSERT(reporter, mockDevice.fDrawBitmapCallCount == 4);
 #endif
 }