Revert of Extract most of the mutable state of SkShader into a separate Context object.

Revert of Extract most of the mutable state of SkShader into a separate Context object. (https://codereview.chromium.org/207683004/)

Reason for revert:
Causing memory leaks in Chromium.

Original issue's description:
> Extract most of the mutable state of SkShader into a separate Context object.
> 
> SkShader currently stores some state during draw calls via setContext(...).
> Move that mutable state into a separate SkShader::Context class that is
> constructed on demand for the duration of the draw.
> 
> Calls to setContext() are replaced with createContext() which returns a context
> corresponding to the shader object or NULL if the parameters to createContext
> are invalid.
> 
> TEST=out/Debug/dm
> BUG=skia:1976
> 
> Committed: http://code.google.com/p/skia/source/detail?r=14216

TBR=scroggo@google.com,skyostil@chromium.org,tomhudson@chromium.org,senorblanco@chromium.org,reed@google.com,dominikg@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=skia:1976
Committed: http://code.google.com/p/skia/source/detail?r=14247

[bungeman-skia, 2014-04-17 21:04:04]

Created Revert of Extract most of the mutable state of SkShader into a separate
Context object.

[commit-bot: I haz the power, 2014-04-17 21:04:25]

CQ is trying da patch. Follow status at
https://skia-tree-status.appspot.com/cq/bungeman@google.com/241283003/1

[commit-bot: I haz the power, 2014-04-17 21:04:35]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-04-17 21:04:35]

Failed to apply patch for include/core/SkComposeShader.h:
While running patch -p1 --forward --force --no-backup-if-mismatch;
  patching file include/core/SkComposeShader.h
  Hunk #1 FAILED at 34.
  1 out of 2 hunks FAILED -- saving rejects to file
include/core/SkComposeShader.h.rej

Patch:       include/core/SkComposeShader.h
Index: include/core/SkComposeShader.h
diff --git a/include/core/SkComposeShader.h b/include/core/SkComposeShader.h
index
9833a9f4ade275ac0fa6fa4358a5edbb5930b826..b54e5efa97e0914dab0564ed940e1f9958607b64
100644
--- a/include/core/SkComposeShader.h
+++ b/include/core/SkComposeShader.h
@@ -34,38 +34,10 @@
     SkComposeShader(SkShader* sA, SkShader* sB, SkXfermode* mode = NULL);
     virtual ~SkComposeShader();
 
-    virtual bool validContext(const SkBitmap&, const SkPaint&,
-                              const SkMatrix&, SkMatrix* totalInverse = NULL)
const SK_OVERRIDE;
-    virtual SkShader::Context* createContext(const SkBitmap&, const SkPaint&,
-                                             const SkMatrix&, void*) const
SK_OVERRIDE;
-    virtual size_t contextSize() const SK_OVERRIDE;
-
-    class ComposeShaderContext : public SkShader::Context {
-    public:
-        // When this object gets destroyed, it will call contextA and
contextB's destructor
-        // but it will NOT free the memory.
-        ComposeShaderContext(const SkComposeShader&, const SkBitmap&,
-                             const SkPaint&, const SkMatrix&,
-                             SkShader::Context* contextA, SkShader::Context*
contextB);
-
-        SkShader::Context* getShaderContextA() const { return fShaderContextA;
}
-        SkShader::Context* getShaderContextB() const { return fShaderContextB;
}
-
-        virtual ~ComposeShaderContext();
-
-        virtual void shadeSpan(int x, int y, SkPMColor[], int count)
SK_OVERRIDE;
-
-    private:
-        SkShader::Context* fShaderContextA;
-        SkShader::Context* fShaderContextB;
-
-        typedef SkShader::Context INHERITED;
-    };
-
-#if SK_DEBUG
-    SkShader* getShaderA() { return fShaderA; }
-    SkShader* getShaderB() { return fShaderB; }
-#endif
+    virtual bool setContext(const SkBitmap&, const SkPaint&,
+                            const SkMatrix&) SK_OVERRIDE;
+    virtual void endContext() SK_OVERRIDE;
+    virtual void shadeSpan(int x, int y, SkPMColor[], int count) SK_OVERRIDE;
 
     SK_TO_STRING_OVERRIDE()
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkComposeShader)
@@ -75,6 +47,7 @@
     virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE;
 
 private:
+
     SkShader*   fShaderA;
     SkShader*   fShaderB;
     SkXfermode* fMode;

[bungeman-skia, 2014-04-17 21:09:16]

The CQ bit was checked by bungeman@google.com

[commit-bot: I haz the power, 2014-04-17 21:09:27]

CQ is trying da patch. Follow status at
https://skia-tree-status.appspot.com/cq/bungeman@google.com/241283003/1

[commit-bot: I haz the power, 2014-04-17 21:10:41]

Change committed as 14247