gpu: workaround force_cube_map_positive_x_allocation fixes Android crash.

gpu/command_buffer/service/texture_manager.cc

Index: gpu/command_buffer/service/texture_manager.cc
diff --git a/gpu/command_buffer/service/texture_manager.cc b/gpu/command_buffer/service/texture_manager.cc
index ed0fd10e5b1e6e1ae96fc5b0316d0be8b10290fb..6ef54d9d7850a9f13b2d43533d582d483c78b9cc 100644
--- a/gpu/command_buffer/service/texture_manager.cc
+++ b/gpu/command_buffer/service/texture_manager.cc
@@ -1939,6 +1939,12 @@ void TextureManager::ValidateAndDoTexImage(
     return;
   }
 
+  if (texture_state->force_cube_map_positive_x_allocation) {
+    DoTexImage2DCubeMapPositiveXIfNeeded(texture_state, state->GetErrorState(),
+                                         framebuffer_state, function_name,
+                                         texture_ref, args);
+  }
+
   DoTexImage(texture_state, state->GetErrorState(), framebuffer_state,
              function_name, texture_ref, args);
 }
@@ -1955,6 +1961,42 @@ GLenum TextureManager::AdjustTexFormat(GLenum format) const {
   return format;
 }
 
+// Nexus 5 crashes on allocating a cube map texture bound to FBO, if
+// the CUBE_MAP_POSITIVE_X texture is not allocated yet.
+void TextureManager::DoTexImage2DCubeMapPositiveXIfNeeded(
+    DecoderTextureState* texture_state,
+    ErrorState* error_state,
+    DecoderFramebufferState* framebuffer_state,
+    const char* function_name,
+    TextureRef* texture_ref,
+    const DoTexImageArguments& args) {
+  switch (args.target) {
+    case GL_TEXTURE_CUBE_MAP_NEGATIVE_X:
+    case GL_TEXTURE_CUBE_MAP_POSITIVE_Y:
+    case GL_TEXTURE_CUBE_MAP_NEGATIVE_Y:
+    case GL_TEXTURE_CUBE_MAP_POSITIVE_Z:
+    case GL_TEXTURE_CUBE_MAP_NEGATIVE_Z:
+      break;
+    default:
+      return;
+  }
+
+  // ValidateTexImage is passed already.
+  Texture* texture = texture_ref->texture();
+  int width = 0;
+  int height = 0;
+  bool positive_x_level_defined = texture->GetLevelSize(
+      GL_TEXTURE_CUBE_MAP_POSITIVE_X, args.level, &width, &height, nullptr);
+  if (!positive_x_level_defined) {
+    DoTexImageArguments positive_x_args = args;
+    positive_x_args.target = GL_TEXTURE_CUBE_MAP_POSITIVE_X;
+    positive_x_args.pixels = nullptr;
+    positive_x_args.pixels_size = 0;

[no sievers, 2015/08/13 18:56:38]

You actually have to get this from ComputeImageDataSizes(), see
HandleTexImage2D(). I think the name is a bit misleading - maybe alloc_size
would be better - but it's used with EnsureGPUMemoryAvailable() so should
specify the size of the allocation even when no pixels are passed in.

[dshwang, 2015/08/14 06:22:56]

|pixels_size| is used in  ValidateTexImage(), not DoTexImage(). It's used to
ensure there is enough memory, not update memory tracker. So I reset, but it
makes code confusing.
I added EnsureGPUMemoryAvailable(2 * args.pixels_size) to ensure two cube faces
allocation, and didn't reset the variable.
In addition, SetLevelInfo() will update the memory consumption in DoTexImage()

+    DoTexImage(texture_state, error_state, framebuffer_state, function_name,
+               texture_ref, positive_x_args);
+  }
+}
+
 void TextureManager::DoTexImage(
     DecoderTextureState* texture_state,
     ErrorState* error_state,