Lazily create shader translators and implement glReleaseShaderCompiler

ANGLE's shader translators hold a significant amount of memory for the
builtin symbols.  By lazily creating the shader translator, it may never
be intialized at all if all compiles hit the program binary cache.

BUG=695135

CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.android:android_optional_gpu_tests_rel

Change-Id: I095dd2efa33e111726db893cd14c3c3574bdd6ce
Reviewed-on: https://chromium-review.googlesource.com/570540Reviewed-by: Kenneth Russell <kbr@chromium.org>
Commit-Queue: Geoff Lang <geofflang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#488317}

gpu/command_buffer/service/gles2_cmd_decoder.cc

@@ -684,6 +684,7 @@ class GLES2DecoderImpl : public GLES2Decoder, public ErrorStateClient {
 
   // Initialize or re-initialize the shader translator.
   bool InitializeShaderTranslator();
+  void DestroyShaderTranslator();
 
   void UpdateCapabilities();
 
@@ -1750,7 +1751,7 @@ class GLES2DecoderImpl : public GLES2Decoder, public ErrorStateClient {
       GLuint renderbuffer, GLenum format);
 
   // Wrapper for glReleaseShaderCompiler.
-  void DoReleaseShaderCompiler() { }
+  void DoReleaseShaderCompiler();
 
   // Wrappers for glSamplerParameter functions.
   void DoSamplerParameterf(GLuint client_id, GLenum pname, GLfloat param);
@@ -2371,6 +2372,7 @@ class GLES2DecoderImpl : public GLES2Decoder, public ErrorStateClient {
   // if not returning an error.
   error::Error current_decoder_error_;
 
+  bool has_fragment_precision_high_ = false;
   scoped_refptr<ShaderTranslatorInterface> vertex_translator_;
   scoped_refptr<ShaderTranslatorInterface> fragment_translator_;
 
@@ -3536,9 +3538,12 @@ bool GLES2DecoderImpl::Initialize(
                               features().khr_robustness ||
                               features().ext_robustness;
 
-  if (!InitializeShaderTranslator()) {
-    return false;
-  }
+  GLint range[2] = {0, 0};
+  GLint precision = 0;
+  QueryShaderPrecisionFormat(gl_version_info(), GL_FRAGMENT_SHADER,
+                             GL_HIGH_FLOAT, range, &precision);
+  has_fragment_precision_high_ =
+      PrecisionMeetsSpecForHighpFloat(range[0], range[1], precision);
 
   GLint viewport_params[4] = { 0 };
   glGetIntegerv(GL_MAX_VIEWPORT_DIMS, viewport_params);
@@ -3894,6 +3899,10 @@ bool GLES2DecoderImpl::InitializeShaderTranslator() {
   if (feature_info_->disable_shader_translator()) {
     return true;
   }
+  if (vertex_translator_ || fragment_translator_) {
+    DCHECK(vertex_translator_ && fragment_translator_);
+    return true;
+  }
   ShBuiltInResources resources;
   sh::InitBuiltInResources(&resources);
   resources.MaxVertexAttribs = group_->max_vertex_attribs();
@@ -3920,12 +3929,7 @@ bool GLES2DecoderImpl::InitializeShaderTranslator() {
     resources.MinProgramTexelOffset = group_->min_program_texel_offset();
   }
 
-  GLint range[2] = { 0, 0 };
-  GLint precision = 0;
-  QueryShaderPrecisionFormat(gl_version_info(), GL_FRAGMENT_SHADER,
-                             GL_HIGH_FLOAT, range, &precision);
-  resources.FragmentPrecisionHigh =
-      PrecisionMeetsSpecForHighpFloat(range[0], range[1], precision);
+  resources.FragmentPrecisionHigh = has_fragment_precision_high_;
 
   ShShaderSpec shader_spec;
   switch (feature_info_->context_type()) {
@@ -4044,6 +4048,11 @@ bool GLES2DecoderImpl::InitializeShaderTranslator() {
   return true;
 }
 
+void GLES2DecoderImpl::DestroyShaderTranslator() {
+  vertex_translator_ = nullptr;
+  fragment_translator_ = nullptr;
+}
+
 bool GLES2DecoderImpl::GenBuffersHelper(GLsizei n, const GLuint* client_ids) {
   for (GLsizei ii = 0; ii < n; ++ii) {
     if (GetBuffer(client_ids[ii])) {
@@ -4905,8 +4914,7 @@ void GLES2DecoderImpl::Destroy(bool have_context) {
 
   // Need to release these before releasing |group_| which may own the
   // ShaderTranslatorCache.
-  fragment_translator_ = NULL;
-  vertex_translator_ = NULL;
+  DestroyShaderTranslator();
 
   // Destroy the GPU Tracer which may own some in process GPU Timings.
   if (gpu_tracer_) {
@@ -8723,6 +8731,10 @@ bool GLES2DecoderImpl::VerifyMultisampleRenderbufferIntegrity(
       pixel[2] == 0xFF);
 }
 
+void GLES2DecoderImpl::DoReleaseShaderCompiler() {
+  DestroyShaderTranslator();
+}
+
 void GLES2DecoderImpl::DoRenderbufferStorage(
   GLenum target, GLenum internalformat, GLsizei width, GLsizei height) {
   Renderbuffer* renderbuffer =
@@ -10552,6 +10564,9 @@ void GLES2DecoderImpl::DoTransformFeedbackVaryings(
 
 scoped_refptr<ShaderTranslatorInterface> GLES2DecoderImpl::GetTranslator(
     GLenum type) {
+  if (!InitializeShaderTranslator()) {
+    return nullptr;
+  }
   return type == GL_VERTEX_SHADER ? vertex_translator_ : fragment_translator_;
 }
 
@@ -15825,7 +15840,7 @@ error::Error GLES2DecoderImpl::HandleRequestExtensionCHROMIUM(
     frag_depth_explicitly_enabled_ |= desire_frag_depth;
     draw_buffers_explicitly_enabled_ |= desire_draw_buffers;
     shader_texture_lod_explicitly_enabled_ |= desire_shader_texture_lod;
-    InitializeShaderTranslator();
+    DestroyShaderTranslator();
   }
 
   if (feature_str.find("GL_CHROMIUM_color_buffer_float_rgba ") !=

gpu/command_buffer/service/shader_manager.cc

@@ -121,6 +121,8 @@ void Shader::DoCompile() {
         << "\n--translated-shader--\n" << source_for_driver
         << "\n--info-log--\n" << log_info_;
   }
+
+  translator_ = nullptr;
 }
 
 void Shader::RefreshTranslatedShaderSource() {