Support for larger than "signed 32b limit" sized bitmaps in BGRAConvolve2D.

src/core/SkConvolver.cpp

Index: src/core/SkConvolver.cpp
diff --git a/src/core/SkConvolver.cpp b/src/core/SkConvolver.cpp
index 7666e6fadc99ac3b161403c91bee35fa0fdbe529..0e97fac07ffc5083cad6d045247c37e388428cd6 100644
--- a/src/core/SkConvolver.cpp
+++ b/src/core/SkConvolver.cpp
@@ -405,7 +405,7 @@ void BGRAConvolve2D(const unsigned char* sourceData,
                 const unsigned char* src[4];
                 unsigned char* outRow[4];
                 for (int i = 0; i < 4; ++i) {
-                    src[i] = &sourceData[(nextXRow + i) * sourceByteRowStride];
+                    src[i] = &sourceData[(uint64_t)(nextXRow + i) * sourceByteRowStride];
                     outRow[i] = rowBuffer.advanceRow();
                 }
                 convolveProcs.fConvolve4RowsHorizontally(src, filterX, outRow);
@@ -416,16 +416,16 @@ void BGRAConvolve2D(const unsigned char* sourceData,
                     nextXRow < lastFilterOffset + lastFilterLength -
                     avoidSimdRows) {
                     convolveProcs.fConvolveHorizontally(
-                        &sourceData[nextXRow * sourceByteRowStride],
+                        &sourceData[(uint64_t)nextXRow * sourceByteRowStride],
                         filterX, rowBuffer.advanceRow(), sourceHasAlpha);
                 } else {
                     if (sourceHasAlpha) {
                         ConvolveHorizontally<true>(
-                            &sourceData[nextXRow * sourceByteRowStride],
+                            &sourceData[(uint64_t)nextXRow * sourceByteRowStride],
                             filterX, rowBuffer.advanceRow());
                     } else {
                         ConvolveHorizontally<false>(
-                            &sourceData[nextXRow * sourceByteRowStride],
+                            &sourceData[(uint64_t)nextXRow * sourceByteRowStride],
                             filterX, rowBuffer.advanceRow());
                     }
                 }