Use SkArenaAlloc in the SkAutoBlitterChoose code.

- Added default implementation of onMakeContext to support use in android.

Searches for uses:
"public SkShader"  package:^chromium$ -file:^src/third_party/skia
package:^aosp.* "public SkShader"  -file:external/skia -file:.*third_party/skia
package:^android$ "public SkShader"  -file:external/skia -file:.*third_party/skia

... shows that no subclass overrides onCreateContext.

TBR=reed@google.com
TBR=mtklein@google.com

Change-Id: I8bd5f57a79534574e344b165d31dccee41c31767
Reviewed-on: https://skia-review.googlesource.com/8140
Commit-Queue: Herb Derby <herb@google.com>
Reviewed-by: Herb Derby <herb@google.com>

1 files changed, 10 insertions, 18 deletions

diff --git a/include/core/SkShader.h b/include/core/SkShader.h
index 30a10dcc9f..4c264e4741 100644
--- a/include/core/SkShader.h
+++ b/include/core/SkShader.h
@@ -17,9 +17,9 @@
 #include "SkPaint.h"
 #include "../gpu/GrColor.h"
 
+class SkArenaAlloc;
 class SkColorFilter;
 class SkColorSpace;
-class SkArenaAlloc;
 class SkImage;
 class SkPath;
 class SkPicture;
@@ -229,15 +229,11 @@ public:
     };
 
     /**
-     *  Create the actual object that does the shading.
-     *  Size of storage must be >= contextSize.
-     */
-    Context* createContext(const ContextRec&, void* storage) const;
-
-    /**
-     *  Return the size of a Context returned by createContext.
+     * Make a context using the memory provided by the arena.
+     *
+     * @return pointer to context or nullptr if can't be created
      */
-    size_t contextSize(const ContextRec&) const;
+    Context* makeContext(const ContextRec&, SkArenaAlloc*) const;
 
 #ifdef SK_SUPPORT_LEGACY_SHADER_ISABITMAP
     /**
@@ -476,16 +472,12 @@ protected:
     bool computeTotalInverse(const ContextRec&, SkMatrix* totalInverse) const;
 
     /**
-     *  Your subclass must also override contextSize() if it overrides onCreateContext().
-     *  Base class impl returns NULL.
+     * Specialize creating a SkShader context using the supplied allocator.
+     * @return pointer to context owned by the arena allocator.
      */
-    virtual Context* onCreateContext(const ContextRec&, void* storage) const;
-
-    /**
-     *  Override this if your subclass overrides createContext, to return the correct size of
-     *  your subclass' context.
-     */
-    virtual size_t onContextSize(const ContextRec&) const;
+    virtual Context* onMakeContext(const ContextRec&, SkArenaAlloc*) const {
+        return nullptr;
+    }
 
     virtual bool onAsLuminanceColor(SkColor*) const {
         return false;