SkiaRenderer: Fix RGB and RGB565 formats

This CL fixes color type that we pass to the skia for the
FBO0. It changes two things:
* Use RGB565 if the surface uses 16 bit format .
* Fallback to RGBA is skia doesn't support rgb color type.

Bug: 1126490

Change-Id: I6f5342ac7bb128134afc2c5182a6c6b99600c7a9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2441311
Commit-Queue: Vasiliy Telezhnikov <vasilyt@chromium.org>
Reviewed-by: Jonathan Backer <backer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#813787}

components/viz/common/features.cc

@@ -111,14 +111,6 @@ bool IsUsingSkiaRenderer() {
   if (IsUsingVizForWebView())
     return true;
 
-#if defined(OS_ANDROID)
-  // https://crbug.com/1126490 Mali-400 with <= 512 MB is currently broken.
-  // Must be checked after IsUsingVizForWebView because it requires
-  // SkiaRenderer.
-  if (base::SysInfo::AmountOfPhysicalMemoryMB() <= 512)
-    return false;
-#endif
-
   return base::FeatureList::IsEnabled(kUseSkiaRenderer) ||
          base::FeatureList::IsEnabled(kVulkan);
 }

components/viz/service/display_embedder/skia_output_device_gl.cc

@@ -125,8 +125,22 @@ SkiaOutputDeviceGL::SkiaOutputDeviceGL(
   }
   CHECK_GL_ERROR();
 
-  auto color_type =
-      (alpha_bits > 0) ? kRGBA_8888_SkColorType : kRGB_888x_SkColorType;
+  auto color_type = kRGBA_8888_SkColorType;
+
+  if (!alpha_bits) {
+    color_type = gl_surface_->GetFormat().GetBufferSize() == 16
+                     ? kRGB_565_SkColorType
+                     : kRGB_888x_SkColorType;
+    // Skia disables RGBx on some GPUs, fallback to RGBA if it's the
+    // case. This doesn't change framebuffer itself, as we already allocated it,
+    // but will change any temporary buffer Skia needs to allocate.
+    if (!context_state_->gr_context()
+             ->defaultBackendFormat(color_type, GrRenderable::kYes)
+             .isValid()) {
+      color_type = kRGBA_8888_SkColorType;
+    }
+  }
+
   capabilities_.sk_color_types[static_cast<int>(gfx::BufferFormat::RGBA_8888)] =
       color_type;
   capabilities_.sk_color_types[static_cast<int>(gfx::BufferFormat::RGBX_8888)] =
@@ -175,6 +189,9 @@ bool SkiaOutputDeviceGL::Reshape(const gfx::Size& size,
     case kRGB_888x_SkColorType:
       framebuffer_info.fFormat = GL_RGB8;
       break;
+    case kRGB_565_SkColorType:
+      framebuffer_info.fFormat = GL_RGB565;
+      break;
     case kRGBA_F16_SkColorType:
       framebuffer_info.fFormat = GL_RGBA16F;
       break;