Revert "Revert of https://codereview.chromium.org/112783004/"

This reverts commit 3293fe57a7507541e9040eab880dcd82c43881f4.

Conflicts:
	src/core/SkScaledImageCache.cpp

BUG=

Review URL: https://codereview.chromium.org/108613005

git-svn-id: http://skia.googlecode.com/svn/trunk@12663 2bbb7eff-a529-9590-31e7-b0007b416f81

2 files changed, 8 insertions, 9 deletions

diff --git a/src/lazy/SkCachingPixelRef.cpp b/src/lazy/SkCachingPixelRef.cpp
index 667a94931b..b7eaf574aa 100644
--- a/src/lazy/SkCachingPixelRef.cpp
+++ b/src/lazy/SkCachingPixelRef.cpp
@@ -90,9 +90,7 @@ void* SkCachingPixelRef::onLockPixels(SkColorTable** colorTable) {
 }
 
 void SkCachingPixelRef::onUnlockPixels() {
-    if (fScaledCacheId != NULL) {
-        SkScaledImageCache::Unlock(
-            static_cast<SkScaledImageCache::ID*>(fScaledCacheId));
-        fScaledCacheId = NULL;
-    }
+    SkASSERT(fScaledCacheId != NULL);
+    SkScaledImageCache::Unlock( static_cast<SkScaledImageCache::ID*>(fScaledCacheId));
+    fScaledCacheId = NULL;
 }
diff --git a/src/lazy/SkDiscardablePixelRef.cpp b/src/lazy/SkDiscardablePixelRef.cpp
index 0b193ade3c..f551436b3b 100644
--- a/src/lazy/SkDiscardablePixelRef.cpp
+++ b/src/lazy/SkDiscardablePixelRef.cpp
@@ -56,14 +56,15 @@ void* SkDiscardablePixelRef::onLockPixels(SkColorTable**) {
     }
     void* pixels = fDiscardableMemory->data();
     if (!fGenerator->getPixels(fInfo, pixels, fRowBytes)) {
-        return NULL;  // TODO(halcanary) Find out correct thing to do.
+        fDiscardableMemory->unlock();
+        SkDELETE(fDiscardableMemory);
+        fDiscardableMemory = NULL;
+        return NULL;
     }
     return pixels;
 }
 void SkDiscardablePixelRef::onUnlockPixels() {
-    if (fDiscardableMemory != NULL) {
-        fDiscardableMemory->unlock();
-    }
+    fDiscardableMemory->unlock();
 }
 
 bool SkInstallDiscardablePixelRef(SkImageGenerator* generator,