diff --git a/RELEASE_NOTES.txt b/RELEASE_NOTES.txt
index 0d0f512..bcb29c4 100644
--- a/RELEASE_NOTES.txt
+++ b/RELEASE_NOTES.txt
@@ -9,6 +9,11 @@
 
   * <insert new release notes here>
 
+  * SkCanvas::drawVertices and drawPatch now support mapping an SkShader without explicit
+    texture coordinates. If they're not supplied, the local positions (vertex position or
+    patch cubic positions) will be directly used to sample the SkShader.
+    https://review.skia.org/290130
+
 * * *
 
 Milestone 84
diff --git a/include/core/SkCanvas.h b/include/core/SkCanvas.h
index 975aab0..440d9b5 100644
--- a/include/core/SkCanvas.h
+++ b/include/core/SkCanvas.h
@@ -2164,8 +2164,11 @@
     }
 
     /** Draws SkVertices vertices, a triangle mesh, using clip and SkMatrix.
-        If vertices texs and vertices colors are defined in vertices, and SkPaint paint
-        contains SkShader, SkBlendMode mode combines vertices colors with SkShader.
+        If paint contains an SkShader and vertices does not contain texCoords, the shader
+        is mapped using the vertices' positions.
+
+        If vertices colors are defined in vertices, and SkPaint paint contains SkShader,
+        SkBlendMode mode combines vertices colors with SkShader.
 
         @param vertices  triangle mesh to draw
         @param mode      combines vertices colors with SkShader, if both are present
@@ -2183,8 +2186,11 @@
     }
 
     /** Draws SkVertices vertices, a triangle mesh, using clip and SkMatrix.
-        If vertices texs and vertices colors are defined in vertices, and SkPaint paint
-        contains SkShader, SkBlendMode mode combines vertices colors with SkShader.
+        If paint contains an SkShader and vertices does not contain texCoords, the shader
+        is mapped using the vertices' positions.
+
+        If vertices colors are defined in vertices, and SkPaint paint contains SkShader,
+        SkBlendMode mode combines vertices colors with SkShader.
 
         @param vertices  triangle mesh to draw
         @param mode      combines vertices colors with SkShader, if both are present
@@ -2217,7 +2223,8 @@
         bottom-right, bottom-left order.
 
         If paint contains SkShader, SkPoint array texCoords maps SkShader as texture to
-        corners in top-left, top-right, bottom-right, bottom-left order.
+        corners in top-left, top-right, bottom-right, bottom-left order. If texCoords is
+        nullptr, SkShader is mapped using positions (derived from cubics).
 
         @param cubics     SkPath cubic array, sharing common points
         @param colors     color array, one for each corner
@@ -2245,7 +2252,8 @@
         bottom-right, bottom-left order.
 
         If paint contains SkShader, SkPoint array texCoords maps SkShader as texture to
-        corners in top-left, top-right, bottom-right, bottom-left order.
+        corners in top-left, top-right, bottom-right, bottom-left order. If texCoords is
+        nullptr, SkShader is mapped using positions (derived from cubics).
 
         @param cubics     SkPath cubic array, sharing common points
         @param colors     color array, one for each corner
diff --git a/src/core/SkCanvas.cpp b/src/core/SkCanvas.cpp
index 78a36e4..65eb6fe 100644
--- a/src/core/SkCanvas.cpp
+++ b/src/core/SkCanvas.cpp
@@ -1967,6 +1967,17 @@
         }
     }
 
+#ifdef SK_BUILD_FOR_ANDROID_FRAMEWORK
+    // Preserve legacy behavior for Android: ignore the SkShader if there are no texCoords present
+    if (paint.getShader() &&
+        !(vertices->priv().hasTexCoords() || vertices->priv().hasCustomData())) {
+        SkPaint noShaderPaint(paint);
+        noShaderPaint.setShader(nullptr);
+        this->onDrawVerticesObject(vertices, mode, noShaderPaint);
+        return;
+    }
+#endif
+
     this->onDrawVerticesObject(vertices, mode, paint);
 }
 
diff --git a/src/core/SkDraw_vertices.cpp b/src/core/SkDraw_vertices.cpp
index 9f605db..fd36f39 100644
--- a/src/core/SkDraw_vertices.cpp
+++ b/src/core/SkDraw_vertices.cpp
@@ -268,11 +268,13 @@
     const uint16_t* indices = info.indices();
     const SkColor* colors = info.colors();
 
-    // make textures and shader mutually consistent
+    // No need for texCoords without shader. If shader is present without explicit texCoords,
+    // use positions instead.
     SkShader* shader = paint.getShader();
-    if (!(shader && textures)) {
-        shader = nullptr;
+    if (!shader) {
         textures = nullptr;
+    } else if (!textures) {
+        textures = positions;
     }
 
     // We can simplify things for certain blendmodes. This is for speed, and SkComposeShader
@@ -351,6 +353,14 @@
                                 // all opaque (and the blendmode will keep them that way
         }
 
+        // Positions as texCoords? The local matrix is always identity, so update once
+        if (textures == positions) {
+            SkMatrix localM;
+            if (!updater->update(ctm, &localM)) {
+                return;
+            }
+        }
+
         auto blitter = SkCreateRasterPipelineBlitter(fDst, p, pipeline, isOpaque, outerAlloc,
                                                      fRC->clipShader());
         while (vertProc(&state)) {
@@ -360,9 +370,9 @@
             }
 
             SkMatrix localM;
-            if (texture_to_matrix(state, positions, textures, &localM) &&
-                updater->update(ctm, &localM))
-            {
+            if ((textures == positions) ||
+                (texture_to_matrix(state, positions, textures, &localM) &&
+                 updater->update(ctm, &localM))) {
                 fill_triangle(state, blitter, *fRC, dev2, dev3);
             }
         }
@@ -378,7 +388,7 @@
 
             const SkMatrixProvider* matrixProvider = fMatrixProvider;
             SkTLazy<SkPreConcatMatrixProvider> preConcatMatrixProvider;
-            if (textures) {
+            if (textures && (textures != positions)) {
                 SkMatrix localM;
                 if (!texture_to_matrix(state, positions, textures, &localM)) {
                     continue;
diff --git a/src/gpu/SkGpuDevice.cpp b/src/gpu/SkGpuDevice.cpp
index 132e67f..df273f6 100644
--- a/src/gpu/SkGpuDevice.cpp
+++ b/src/gpu/SkGpuDevice.cpp
@@ -940,12 +940,11 @@
                                 const SkPaint& skPaint,
                                 const SkMatrixProvider& matrixProvider,
                                 SkBlendMode bmode,
-                                bool hasTexs,
                                 bool hasColors,
                                 GrPaint* grPaint) {
-    if (hasTexs && skPaint.getShader()) {
+    if (skPaint.getShader()) {
         if (hasColors) {
-            // When there are texs and colors the shader and colors are combined using bmode.
+            // When there are colors and a shader, the shader and colors are combined using bmode.
             return SkPaintToGrPaintWithXfermode(context, colorInfo, skPaint, matrixProvider, bmode,
                                                 grPaint);
         } else {
@@ -954,12 +953,11 @@
         }
     } else {
         if (hasColors) {
-            // We have colors, but either have no shader or no texture coords (which implies that
-            // we should ignore the shader).
+            // We have colors, but no shader.
             return SkPaintToGrPaintWithPrimitiveColor(context, colorInfo, skPaint, matrixProvider,
                                                       grPaint);
         } else {
-            // No colors and no shaders. Just draw with the paint color.
+            // No colors and no shader. Just draw with the paint color.
             return SkPaintToGrPaintNoShader(context, colorInfo, skPaint, matrixProvider, grPaint);
         }
     }
@@ -975,13 +973,9 @@
     const SkRuntimeEffect* effect =
             paint.getShader() ? as_SB(paint.getShader())->asRuntimeEffect() : nullptr;
 
-    // Pretend that we have tex coords when using custom per-vertex data. The shader is going to
-    // use those (rather than local coords), but our paint conversion remains the same.
     GrPaint grPaint;
-    bool hasColors = info.hasColors();
-    bool hasTexs = info.hasTexCoords() || info.hasCustomData();
     if (!init_vertices_paint(fContext.get(), fRenderTargetContext->colorInfo(), paint,
-                             this->asMatrixProvider(), mode, hasTexs, hasColors, &grPaint)) {
+                             this->asMatrixProvider(), mode, info.hasColors(), &grPaint)) {
         return;
     }
     fRenderTargetContext->drawVertices(this->clip(), std::move(grPaint), this->asMatrixProvider(),