Added runtime checks for GetClientRect errors.
Added runtime checks for GetClientRect errors.

I noticed that if the window handle is invalid, the resulting rect will be uninitialized. This change makes it fail immediately.

Review URL: http://codereview.appspot.com/2009042

git-svn-id: a070b70d2b8c44c266a3870c0cddd9a0ee470458@386 736b8ea6-26fd-11df-bfd4-992fa37f6226

ecoal95/angle,MSOpenTech/angle,themusicgod1/angleproject,xin3liang/platform_external_chromium_org_third_party_angle,csa7mdm/angle,cvsuser-chromium/chromium-third-party_angle_dx11,pombreda/angleproject,vvuk/angle,vvuk/angle,shairai/angleproject,domokit/waterfall,stammen/angleproject,cantren/angleproject,jgcaaprom/android_external_chromium_org_third_party_angle,ppy/angle,xin3liang/platform_external_chromium_org_third_party_angle_dx11,xin3liang/platform_external_chromium_org_third_party_angle,KalebDark/angleproject,vvuk/angle,crezefire/angle,stammen/angleproject,xin3liang/platform_external_chromium_org_third_party_angle_dx11,ppy/angle,cvsuser-chromium/chromium-third-party_angle_dx11,ecoal95/angle,KalebDark/angleproject,jgcaaprom/android_external_chromium_org_third_party_angle,RepublicMaster/angleproject,ghostoy/angle,nandhanurrevanth/angle,MIPS/external-chromium_org-third_party-angle_dx11,csa7mdm/angle,cvsuser-chromium/chromium-third-party_angle_dx11,nandhanurrevanth/angle,MSOpenTech/angle-win8.0,vvuk/angle-old,geekboxzone/lollipop_external_chromium_org_third_party_angle,geekboxzone/lollipop_external_chromium_org_third_party_angle,geekboxzone/lollipop_external_chromium_org_third_party_angle,pombreda/angleproject,mrobinson/rust-angle,KTXSoftware/angleproject,mybios/angle,shairai/angleproject,MIPS/external-chromium_org-third_party-angle_dx11,mikolalysenko/angle,android-ia/platform_external_chromium_org_third_party_angle,KTXSoftware/angleproject,RepublicMaster/angleproject,ehsan/angle,ecoal95/angle,RepublicMaster/angleproject,vvuk/angle-old,mlfarrell/angle,shairai/angleproject,xuxiandi/angleproject,mlfarrell/angle,crezefire/angle,themusicgod1/angleproject,ghostoy/angle,mrobinson/rust-angle,MSOpenTech/angle-win8.0,xin3liang/platform_external_chromium_org_third_party_angle_dx11,xuxiandi/angleproject,ehsan/angle,bsergean/angle,KalebDark/angleproject,MIPS/external-chromium_org-third_party-angle,android-ia/platform_external_chromium_org_third_party_angle,MSOpenTech/angle-win8.0,mrobinson/rust-angle,vvuk/angle,cantren/angleproject,MIPS/external-chromium_org-third_party-angle,mikolalysenko/angle,RepublicMaster/angleproject,xin3liang/platform_external_chromium_org_third_party_angle,geekboxzone/lollipop_external_chromium_org_third_party_angle,cvsuser-chromium/chromium-third-party_angle_dx11,bsergean/angle,MIPS/external-chromium_org-third_party-angle_dx11,MIPS/external-chromium_org-third_party-angle,larsbergstrom/angle,MSOpenTech/angle,themusicgod1/angleproject,jgcaaprom/android_external_chromium_org_third_party_angle,ehsan/angle,ecoal95/angle,bsergean/angle,android-ia/platform_external_chromium_org_third_party_angle,nandhanurrevanth/angle,ghostoy/angle,larsbergstrom/angle,ppy/angle,MSOpenTech/angle,xin3liang/platform_external_chromium_org_third_party_angle,larsbergstrom/angle,mybios/angle,vvuk/angle-old,jgcaaprom/android_external_chromium_org_third_party_angle,larsbergstrom/angle,ehsan/angle,mlfarrell/angle,stammen/angleproject,mybios/angle,themusicgod1/angleproject,vvuk/angle-old,xuxiandi/angleproject,pombreda/angleproject,bsergean/angle,mikolalysenko/angle,KTXSoftware/angleproject,mrobinson/rust-angle,crezefire/angle,nandhanurrevanth/angle,MSOpenTech/angle-win8.0,KTXSoftware/angleproject,android-ia/platform_external_chromium_org_third_party_angle_dx11,ecoal95/angle,stammen/angleproject,KTXSoftware/angleproject,pombreda/angleproject,xin3liang/platform_external_chromium_org_third_party_angle_dx11,ppy/angle,mlfarrell/angle,KalebDark/angleproject,mrobinson/rust-angle,android-ia/platform_external_chromium_org_third_party_angle,csa7mdm/angle,xuxiandi/angleproject,csa7mdm/angle,mikolalysenko/angle,android-ia/platform_external_chromium_org_third_party_angle_dx11,android-ia/platform_external_chromium_org_third_party_angle_dx11,cantren/angleproject,ghostoy/angle,cantren/angleproject,shairai/angleproject,crezefire/angle,domokit/waterfall,MSOpenTech/angle,MIPS/external-chromium_org-third_party-angle_dx11,mybios/angle,MIPS/external-chromium_org-third_party-angle,android-ia/platform_external_chromium_org_third_party_angle_dx11