Work more on getting things built with -Wimplicit-fallthrough.

This CL was uploaded by git cl split.

R=kbr@chromium.org

Bug: 177475
Cq-Include-Trybots: master.tryserver.chromium.android:android_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel
Change-Id: I36c23dfa011f28bb190540b9bd8ee78de68dc4bd
Reviewed-on: https://chromium-review.googlesource.com/889732Reviewed-by: Kenneth Russell <kbr@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#533022}

third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.cpp

@@ -873,6 +873,7 @@ void WebGL2RenderingContextBase::RenderbufferStorageImpl(
                           "for integer formats, samples > 0");
         return;
       }
+      FALLTHROUGH;
     case GL_R8:
     case GL_RG8:
     case GL_RGB8:
@@ -5521,6 +5522,7 @@ ScriptValue WebGL2RenderingContextBase::getFramebufferAttachmentParameter(
     case GL_FRAMEBUFFER_ATTACHMENT_TEXTURE_LEVEL:
       if (!attachment_object->IsTexture())
         break;
+      FALLTHROUGH;
     case GL_FRAMEBUFFER_ATTACHMENT_RED_SIZE:
     case GL_FRAMEBUFFER_ATTACHMENT_GREEN_SIZE:
     case GL_FRAMEBUFFER_ATTACHMENT_BLUE_SIZE:
@@ -5539,6 +5541,7 @@ ScriptValue WebGL2RenderingContextBase::getFramebufferAttachmentParameter(
             "COMPONENT_TYPE can't be queried for DEPTH_STENCIL_ATTACHMENT");
         return ScriptValue::CreateNull(script_state);
       }
+      FALLTHROUGH;
     case GL_FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING: {
       GLint value = 0;
       ContextGL()->GetFramebufferAttachmentParameteriv(target, attachment,

third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.cpp

@@ -3244,6 +3244,7 @@ ScriptValue WebGLRenderingContextBase::getProgramParameter(
                           "invalid parameter name");
         return ScriptValue::CreateNull(script_state);
       }
+      FALLTHROUGH;
     case GL_ATTACHED_SHADERS:
     case GL_ACTIVE_ATTRIBUTES:
     case GL_ACTIVE_UNIFORMS:
@@ -3254,6 +3255,7 @@ ScriptValue WebGLRenderingContextBase::getProgramParameter(
         ContextGL()->GetProgramiv(ObjectOrZero(program), pname, &value);
         return WebGLAny(script_state, static_cast<unsigned>(value));
       }
+      FALLTHROUGH;
     default:
       SynthesizeGLError(GL_INVALID_ENUM, "getProgramParameter",
                         "invalid parameter name");
@@ -3293,6 +3295,7 @@ ScriptValue WebGLRenderingContextBase::getRenderbufferParameter(
                           "invalid parameter name");
         return ScriptValue::CreateNull(script_state);
       }
+      FALLTHROUGH;
     case GL_RENDERBUFFER_WIDTH:
     case GL_RENDERBUFFER_HEIGHT:
     case GL_RENDERBUFFER_RED_SIZE:
@@ -3783,7 +3786,7 @@ ScriptValue WebGLRenderingContextBase::getVertexAttrib(
         ContextGL()->GetVertexAttribiv(index, pname, &value);
         return WebGLAny(script_state, static_cast<bool>(value));
       }
-    // fall through to default error case
+      FALLTHROUGH;
     default:
       SynthesizeGLError(GL_INVALID_ENUM, "getVertexAttrib",
                         "invalid parameter name");
@@ -5541,12 +5544,12 @@ void WebGLRenderingContextBase::TexParameter(GLenum target,
     case GL_TEXTURE_MAG_FILTER:
       break;
     case GL_TEXTURE_WRAP_R:
-      // fall through to WRAP_S and WRAP_T for WebGL 2 or higher
       if (!IsWebGL2OrHigher()) {
         SynthesizeGLError(GL_INVALID_ENUM, "texParameter",
                           "invalid parameter name");
         return;
       }
+      FALLTHROUGH;
     case GL_TEXTURE_WRAP_S:
     case GL_TEXTURE_WRAP_T:
       if ((is_float && paramf != GL_CLAMP_TO_EDGE &&
@@ -6924,6 +6927,7 @@ bool WebGLRenderingContextBase::ValidateTexFuncDimensions(
         }
         break;
       }
+      FALLTHROUGH;
     case GL_TEXTURE_2D_ARRAY:
       if (IsWebGL2OrHigher()) {
         if (width > (max_texture_size_ >> level) ||
@@ -6935,6 +6939,7 @@ bool WebGLRenderingContextBase::ValidateTexFuncDimensions(
         }
         break;
       }
+      FALLTHROUGH;
     default:
       SynthesizeGLError(GL_INVALID_ENUM, function_name, "invalid target");
       return false;