Send less transform data when drawing text with nvpr

src/gpu/GrStencilAndCoverTextContext.h

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrStencilAndCoverTextContext_DEFINED
 #define GrStencilAndCoverTextContext_DEFINED
 
 #include "GrTextContext.h"
 #include "GrDrawState.h"
+#include "GrDrawTarget.h"
 #include "SkStrokeRec.h"
 
 class GrTextStrike;
 class GrPath;
 
 /*
  * This class implements text rendering using stencil and cover path rendering
  * (by the means of GrDrawTarget::drawPath).
  * This class exposes the functionality through GrTextContext interface.
  */
 class GrStencilAndCoverTextContext : public GrTextContext {
 public:
     GrStencilAndCoverTextContext(GrContext*, const SkDeviceProperties&);
     virtual ~GrStencilAndCoverTextContext();
 
     virtual void drawText(const GrPaint&, const SkPaint&, const char text[],
                           size_t byteLength,
                           SkScalar x, SkScalar y) SK_OVERRIDE;
     virtual void drawPosText(const GrPaint&, const SkPaint&,
                              const char text[], size_t byteLength,
                              const SkScalar pos[], SkScalar constY,
                              int scalarsPerPosition) SK_OVERRIDE;
 
     virtual bool canDraw(const SkPaint& paint) SK_OVERRIDE;
 
 private:
     class GlyphPathRange;
     static const int kGlyphBufferSize = 1024;
 
-    void init(const GrPaint&, const SkPaint&, size_t textByteLength);
+    enum DeviceSpaceGlyphsBehavior {
+        kUseIfNeeded_DeviceSpaceGlyphsBehavior,
+        kDoNotUse_DeviceSpaceGlyphsBehavior,
+    };
+    void init(const GrPaint&, const SkPaint&, size_t textByteLength,
+              DeviceSpaceGlyphsBehavior, SkScalar textTranslateY = 0);
     void initGlyphs(SkGlyphCache* cache);
+    void appendGlyph(uint16_t glyphID, float x);
     void appendGlyph(uint16_t glyphID, float x, float y);
     void flush();
     void finish();
 
     GrDrawState::AutoRestoreEffects fStateRestore;
     SkScalar fTextRatio;
+    float fTextInverseRatio;
     SkStrokeRec fStroke;
     SkGlyphCache* fGlyphCache;
     GlyphPathRange* fGlyphs;
     uint32_t fIndexBuffer[kGlyphBufferSize];
-    float fTransformBuffer[6 * kGlyphBufferSize];
+    float fTransformBuffer[2 * kGlyphBufferSize];
+    GrDrawTarget::PathTransformType fTransformType;
     int fPendingGlyphCount;
-    SkMatrix fGlyphTransform;
+    SkMatrix fContextInitialMatrix;
     bool fNeedsDeviceSpaceGlyphs;
 };
 
 #endif