diff -r 000000000000 -r 6474c204b198 gfx/skia/trunk/src/effects/SkTransparentShader.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/skia/trunk/src/effects/SkTransparentShader.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,117 @@
+
+/*
+ * Copyright 2006 The Android Open Source Project
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+
+#include "SkTransparentShader.h"
+#include "SkColorPriv.h"
+#include "SkString.h"
+
+bool SkTransparentShader::setContext(const SkBitmap& device,
+                                     const SkPaint& paint,
+                                     const SkMatrix& matrix) {
+    fDevice = &device;
+    fAlpha = paint.getAlpha();
+
+    return this->INHERITED::setContext(device, paint, matrix);
+}
+
+uint32_t SkTransparentShader::getFlags() {
+    uint32_t flags = this->INHERITED::getFlags();
+
+    switch (fDevice->colorType()) {
+        case kRGB_565_SkColorType:
+            flags |= kHasSpan16_Flag;
+            if (fAlpha == 255)
+                flags |= kOpaqueAlpha_Flag;
+            break;
+        case kPMColor_SkColorType:
+            if (fAlpha == 255 && fDevice->isOpaque())
+                flags |= kOpaqueAlpha_Flag;
+            break;
+        default:
+            break;
+    }
+    return flags;
+}
+
+void SkTransparentShader::shadeSpan(int x, int y, SkPMColor span[], int count) {
+    unsigned scale = SkAlpha255To256(fAlpha);
+
+    switch (fDevice->colorType()) {
+        case kPMColor_SkColorType:
+            if (scale == 256) {
+                SkPMColor* src = fDevice->getAddr32(x, y);
+                if (src != span) {
+                    memcpy(span, src, count * sizeof(SkPMColor));
+                }
+            } else {
+                const SkPMColor* src = fDevice->getAddr32(x, y);
+                for (int i = count - 1; i >= 0; --i) {
+                    span[i] = SkAlphaMulQ(src[i], scale);
+                }
+            }
+            break;
+        case kRGB_565_SkColorType: {
+            const uint16_t* src = fDevice->getAddr16(x, y);
+            if (scale == 256) {
+                for (int i = count - 1; i >= 0; --i) {
+                    span[i] = SkPixel16ToPixel32(src[i]);
+                }
+            } else {
+                unsigned alpha = fAlpha;
+                for (int i = count - 1; i >= 0; --i) {
+                    uint16_t c = src[i];
+                    unsigned r = SkPacked16ToR32(c);
+                    unsigned g = SkPacked16ToG32(c);
+                    unsigned b = SkPacked16ToB32(c);
+
+                    span[i] = SkPackARGB32( alpha,
+                                            SkAlphaMul(r, scale),
+                                            SkAlphaMul(g, scale),
+                                            SkAlphaMul(b, scale));
+                }
+            }
+            break;
+        }
+        case kAlpha_8_SkColorType: {
+            const uint8_t* src = fDevice->getAddr8(x, y);
+            if (scale == 256) {
+                for (int i = count - 1; i >= 0; --i) {
+                    span[i] = SkPackARGB32(src[i], 0, 0, 0);
+                }
+            } else {
+                for (int i = count - 1; i >= 0; --i) {
+                    span[i] = SkPackARGB32(SkAlphaMul(src[i], scale), 0, 0, 0);
+                }
+            }
+            break;
+        }
+        default:
+            SkDEBUGFAIL("colorType not supported as a destination device");
+            break;
+    }
+}
+
+void SkTransparentShader::shadeSpan16(int x, int y, uint16_t span[], int count) {
+    SkASSERT(fDevice->colorType() == kRGB_565_SkColorType);
+
+    uint16_t* src = fDevice->getAddr16(x, y);
+    if (src != span) {
+        memcpy(span, src, count << 1);
+    }
+}
+
+#ifndef SK_IGNORE_TO_STRING
+void SkTransparentShader::toString(SkString* str) const {
+    str->append("SkTransparentShader: (");
+
+    this->INHERITED::toString(str);
+
+    str->append(")");
+}
+#endif