Remove all instances of incorrect coverage with DMSAA

Here we pivot and handle DMSAA differently depending on platform:

1) Desktop GL and EXT_multisample_compatibility: Here it's easy to use
   all our existing coverage ops because we can just call
   glDisable(GL_MULTISAMPLE). So we only trigger MSAA for paths and
   use the coverage ops for everything else with MSAA disabled.

2) EXT_multisampled_render_to_to_texture (86% adoption on Android):
   The assumption here is that MSAA is almost free. So we just allow
   MSAA to be triggered often and don't worry about it.

Devices that neither support #1 nor #2 just don't get DMSAA for now.

Bug: skia:11396
Change-Id: I53ad840216ea6d88ae69eece6f7a062f9e82dad7
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/421019
Commit-Queue: Chris Dalton <csmartdalton@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
diff --git a/src/gpu/ops/GrDashLinePathRenderer.cpp b/src/gpu/ops/GrDashLinePathRenderer.cpp
index dfa2967..eda3392 100644
--- a/src/gpu/ops/GrDashLinePathRenderer.cpp
+++ b/src/gpu/ops/GrDashLinePathRenderer.cpp
@@ -37,15 +37,9 @@
             aaMode = GrDashOp::AAMode::kNone;
             break;
         case GrAAType::kMSAA:
-            if (args.fSurfaceDrawContext->canUseDynamicMSAA()) {
-                // In DMSAA we avoid using MSAA, in order to reduce the number of MSAA triggers.
-                aaMode = GrDashOp::AAMode::kCoverage;
-            } else {
-                // In this mode we will use aa between dashes but the outer border uses MSAA.
-                // Otherwise, we can wind up with external edges antialiased and internal edges
-                // unantialiased.
-                aaMode = GrDashOp::AAMode::kCoverageWithMSAA;
-            }
+            // In this mode we will use aa between dashes but the outer border uses MSAA. Otherwise,
+            // we can wind up with external edges antialiased and internal edges unantialiased.
+            aaMode = GrDashOp::AAMode::kCoverageWithMSAA;
             break;
         case GrAAType::kCoverage:
             aaMode = GrDashOp::AAMode::kCoverage;