Vulkan: renderer->finish() before reading buffers.

Have to call renderer->finish() before reading a buffer otherwise you can
get stale data.
Enable IndexBufferOffsetTest.UInt8Index/ES2_VULKAN which now works.
Disable LineLoopTest.LineLoopUShortIndexBuffer/ES2_VULKAN which stopped
working on Windows with Intel GPU.

BUG=angleproject:2659

Change-Id: I1e21b0e1dacd3368923caf18e767e34ab696eef6
Reviewed-on: https://chromium-review.googlesource.com/1227032
Commit-Queue: Frank Henigman <fjhenigman@chromium.org>
Reviewed-by: Yuly Novikov <ynovikov@chromium.org>

src/libANGLE/renderer/vulkan/BufferVk.cpp

@@ -173,6 +173,9 @@ gl::Error BufferVk::getIndexRange(const gl::Context *context,
 {
     ContextVk *contextVk = vk::GetImpl(context);
 
+    // Needed before reading buffer or we could get stale data.
+    ANGLE_TRY(contextVk->getRenderer()->finish(contextVk));
+
     // TODO(jmadill): Consider keeping a shadow system memory copy in some cases.
     ASSERT(mBuffer.valid());
 

src/libANGLE/renderer/vulkan/VertexArrayVk.cpp

@@ -159,7 +159,7 @@ angle::Result VertexArrayVk::convertVertexBuffer(ContextVk *contextVk,
                                                  size_t attribIndex)
 {
 
-    // Preparation for mapping source buffer.
+    // Needed before reading buffer or we could get stale data.
     ANGLE_TRY(contextVk->getRenderer()->finish(contextVk));
 
     unsigned srcFormatSize = mCurrentArrayBufferFormats[attribIndex]->angleFormat().pixelBytes;
@@ -541,6 +541,9 @@ angle::Result VertexArrayVk::updateIndexTranslation(ContextVk *contextVk,
     }
     else
     {
+        // Needed before reading buffer or we could get stale data.
+        ANGLE_TRY(contextVk->getRenderer()->finish(contextVk));
+
         ASSERT(drawCallParams.type() == GL_UNSIGNED_BYTE);
         // Unsigned bytes don't have direct support in Vulkan so we have to expand the
         // memory to a GLushort.

src/tests/gl_tests/IndexBufferOffsetTest.cpp

@@ -118,10 +118,6 @@ class IndexBufferOffsetTest : public ANGLETest
 // Test using an offset for an UInt8 index buffer
 TEST_P(IndexBufferOffsetTest, UInt8Index)
 {
-    // TODO(lucferron): Add support for unsigned byte elements array buffers
-    // http://anglebug.com/2659
-    ANGLE_SKIP_TEST_IF(IsVulkan());
-
     GLubyte indexData[] = {0, 1, 2, 1, 2, 3};
     runTest(GL_UNSIGNED_BYTE, 1, indexData);
 }

src/tests/gl_tests/LineLoopTest.cpp

@@ -152,6 +152,10 @@ TEST_P(LineLoopTest, LineLoopUByteIndexBuffer)
 
 TEST_P(LineLoopTest, LineLoopUShortIndexBuffer)
 {
+    // TODO(fjhenigman): Probabe driver bug. Work around it and/or notify vendor.
+    // http://anglebug.com/2838
+    ANGLE_SKIP_TEST_IF(IsVulkan() && IsWindows() && IsIntel());
+
     // Disable D3D11 SDK Layers warnings checks, see ANGLE issue 667 for details
     ignoreD3D11SDKLayersWarnings();