Reland "Don't require mips in GrTextureProducer if texture is 1x1."

This reverts commit c861eee3a6f1f93ad3df27b8be94f44b245bd128.

Reason for revert: Relanding with fix for gray8 not copyable

Original change's description:
> Revert "Don't require mips in GrTextureProducer if texture is 1x1."
>
> This reverts commit 5191fd7555d34225ef771ad4cac65bcbbb50a89c.
>
> Reason for revert: breaking angle
>
> Original change's description:
> > Don't require mips in GrTextureProducer if texture is 1x1.
> >
> > Bug: chromium:862921
> > Change-Id: I5f3584ad36e160a5a09d0a37e31e147155076b4d
> > Reviewed-on: https://skia-review.googlesource.com/142586
> > Reviewed-by: Brian Osman <brianosman@google.com>
> > Reviewed-by: Brian Salomon <bsalomon@google.com>
> > Commit-Queue: Greg Daniel <egdaniel@google.com>
>
> TBR=egdaniel@google.com,bsalomon@google.com,brianosman@google.com
>
> Change-Id: Iaef7a56b061cb41f4c75ec20d8df77d3e52b194d
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Bug: chromium:862921
> Reviewed-on: https://skia-review.googlesource.com/142600
> Reviewed-by: Greg Daniel <egdaniel@google.com>
> Commit-Queue: Greg Daniel <egdaniel@google.com>

TBR=egdaniel@google.com,bsalomon@google.com,brianosman@google.com

Change-Id: I52378fa43efe2fdf583335f5fa8aa5b04a68ae2f
Bug: chromium:862921
Reviewed-on: https://skia-review.googlesource.com/142760
Commit-Queue: Greg Daniel <egdaniel@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
diff --git a/tests/GrMipMappedTest.cpp b/tests/GrMipMappedTest.cpp
index 3c47598..ee4838d 100644
--- a/tests/GrMipMappedTest.cpp
+++ b/tests/GrMipMappedTest.cpp
@@ -289,3 +289,40 @@
         }
     }
 }
+
+// Test that we don't create a mip mapped texture if the size is 1x1 even if the filter mode is set
+// to use mips. This test passes by not crashing or hitting asserts in code.
+DEF_GPUTEST_FOR_RENDERING_CONTEXTS(Gr1x1TextureMipMappedTest, reporter, ctxInfo) {
+    GrContext* context = ctxInfo.grContext();
+    if (!context->contextPriv().caps()->mipMapSupport()) {
+        return;
+    }
+
+    // Make surface to draw into
+    SkImageInfo info = SkImageInfo::MakeN32(16, 16, kPremul_SkAlphaType);
+    sk_sp<SkSurface> surface = SkSurface::MakeRenderTarget(context, SkBudgeted::kNo, info);
+
+    // Make 1x1 raster bitmap
+    SkBitmap bmp;
+    bmp.allocN32Pixels(1, 1);
+    SkPMColor* pixel = reinterpret_cast<SkPMColor*>(bmp.getPixels());
+    *pixel = 0;
+
+    sk_sp<SkImage> bmpImage = SkImage::MakeFromBitmap(bmp);
+
+    // Make sure we scale so we don't optimize out the use of mips.
+    surface->getCanvas()->scale(0.5f, 0.5f);
+
+    SkPaint paint;
+    // This should upload the image to a non mipped GrTextureProxy.
+    surface->getCanvas()->drawImage(bmpImage, 0, 0, &paint);
+    surface->flush();
+
+    // Now set the filter quality to high so we use mip maps. We should find the non mipped texture
+    // in the cache for the SkImage. Since the texture is 1x1 we should just use that texture
+    // instead of trying to do a copy to a mipped texture.
+    paint.setFilterQuality(kHigh_SkFilterQuality);
+    surface->getCanvas()->drawImage(bmpImage, 0, 0, &paint);
+    surface->flush();
+}
+